taxonID	type	description	language	source
7A1887E1A264FFBCFF2D6F723F8658E6.taxon	description	Figure 4	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A264FFBCFF2D6F723F8658E6.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 27 ′ 48 ″ N, 062 ° 47 ′ 33 ″ W; 14 m a. s. l.; 8 Jul. 2019; habitat: river delta, with silty sand and rocks as substrates; QFA 0634995. Identification. Plants 2.5 – 5.5 cm high; herbaceous; not caespitose. Taproots present. Stems 1.5 – 4.0 cm long; ascending or erect; glabrous. Leaves basal; horizontal or patent; alternate; petiolate. Petioles 2 – 7 mm long; winged; glabrous. Leaf blades 5 – 25 mm long, 1 – 6 mm wide; oblanceolate; unlobed or dentate, with 1 – 3 triangular, acute lobes on each side; dark green; abaxial and adaxial surfaces both glabrous; margins glabrous; apices obtuse or acute. Calyculi 1.5 – 5.0 mm long; appressed or spreading; ovate; dark green or dark purple; surface glabrous; apices acute. Phyllaries 7 – 15 mm long; appressed; lanceolate; dark green or dark purple; surface glabrous. Inflorescence a solitary capitulum; 13 – 20 mm wide; with 30 – 40 zygomorphic florets. Sepals represented by pappi; 4 – 7 mm long; pale yellow or white. Petals 5; fused; pale yellow. Ray floret limbs 6 – 12 mm long, 1 – 4 mm wide; ligulate. Androecium with 5 stamens and 3 – 5 mm long anther tubes. Gynoecium with 1 style and 2 stigmas. Fruit an achene. Taraxacum phymatocarpum can be differentiated from the three other Taraxacum F. H. Wiggers species present on Ellesmere Island (T. ceratophorum (Ledebour) de Candolle, T. holmenianum Sahlin, and T. hyparcticum Dahlstedt; Aiken et al. 2007; GBIF 2020) by the following: plant height <10 cm; flowering head small (15 – 20 mm wide); petals yellow without pink-grey stripes (as in T. hyparcticum); and ligulate floret limbs ≤ 9 mm wide (Brouillet 2006; Aiken et al. 2007). Brassicaceae – Draba family Braya purpurascens (R. Brown) Bunge ex Ledebour Syn.: Braya glabella Richardson subsp. purpurascens (R. Brown) Cody Figure 5 A Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 28 ′ 11 ″ N, 062 ° 41 ′ 60 ″ W; 154 m a. s. l.; 14 Aug. 2019; habitat: xeric, with polygonal patterned ground made of till and rocks, and sparse dominance of Saxifraga oppositifolia Linnaeus; QFA 0635558 • same locality; 82 ° 29 ′ 46 ″ N, 062 ° 44 ′ 07 ″ W; 30 m a. s. l.; 4 Jul. 2019; habitat: barren ground in a slope, with till and rocks as substrates, and sparse dominance of Saxifraga oppositifolia; QFA 0635559 • same locality; 82 ° 27 ′ 48 ″ N, 062 ° 47 ′ 33 ″ W; 14 m a. s. l.; 8 Jul. 2019; habitat: river delta, with silty sand and rocks as substrates; QFA 0635560. Identification. Plants 1.5 – 4.5 cm high; herbaceous; caespitose. Taproots present. Stems 0.5 – 4.0 cm long; erect, ascending, or decumbent; hairy, with simple and branched hairs (2 rays: Y, T, and V). Leaves basal; alternate; petiolate. Petioles 2 – 5 mm long; winged; margins ciliate, with simple hairs. Leaf blades 4 – 19 mm long, 0.8 – 2.7 mm wide; linear or oblanceolate; unlobed or lobed, with 1 – 2 triangular acute lobes on each side; bases attenuate; abaxial and adaxial surfaces both shiny (living specimens) and glabrous; margins ciliate, with simple hairs; apices acute or obtuse. Inflorescence a cor- ymbiform raceme, with 2 – 6 flowers; not elongating or slightly elongating as the fruit matures. Pedicels glabrous or sparsely hairy. Sepals 4; 1.7 – 2.9 mm long, 0.8 – 1.9 mm wide; ovate or oblong; purple; surface glabrous; margins glabrous or ciliate, with simple hairs; apices rounded. Petals 4; 2.4 – 3.8 mm long, 0.8 – 1.6 mm wide; obovate or obtrullate; unlobed; white and purple-tinged proximally. Androecium with 6 stamens and 0.3 – 0.5 mm long anthers. Gynoecium with 1 style and 1 stigma. Fruit a silique; 5.0 – 10.2 mm long, 1.5 – 3.0 mm wide; elliptic or oblanceolate; cylindrical; yellowish purple or greyish green; surface glabrous or sparsely hairy, with simple and branched hairs (2 rays: T and V). Styles are persisting in fruit 0.7 – 1.2 mm long, 0.2 – 0.4 mm wide. Stigmas 0.5 – 0.7 mm wide; larger than the styles. Braya Sternberg & Hoppe species can be differenti- ated from white-flowered Draba Linnaeus species by the terete or ovoid fruits; ciliate sepal margins; and presence of simple and 2 - forked hairs on the leaves (Aiken et al. 2007; Saarela et al. 2020). Among the four Braya species present on Ellesmere Island (GBIF 2020), B. purpurascens, B. thorild-wulffii Ostenfeld subsp. thorild-wulffii, and B. glabella subsp. glabella and subsp. prostrata J. G. Harris have one or no cauline leaf and ovoid to cylindrical-elliptic fruits, whereas B. humilis (C. A. Meyer) B. L. Robinson subsp. humilis and subsp. ellesmerensis J. G. Harris have more than one cauline leaf and linear fruits (Aiken et al. 2007; Harris 2010; Saarela et al. 2020). B. thorild-wulffii subsp. thorild-wulffii and B. glabella subsp. prostrata have decumbent to prostrate stems, whereas B. purpurascens and B. glabella subsp. glabella have erect or ascending stems (Harris 2006, 2010). B. thorild-wulffii subsp. thorild-wulffii has short styles persisting in fruits (0 – 1 mm long), whereas B. purpurascens and both B. glabella subspecies have mostly longer styles (0.3 – 2.0 mm long; Harris 2006, 2010). The fruits of B. purpurascens and both B. glabella subspecies are oblong, ovoid-elliptic, or cylindrical-lanceolate, whereas they are ovoid or globose in B. thorild-wulffii subsp. thorild-wulffii (Harris 2006; Saarela et al. 2020). Fruits of B. glabella subsp. glabella are oblong or narrowly oblong-lanceoloid, often curved, and 3.5 – 8.3 times as long as wide, whereas they are ovoid-elliptic or oblong-elliptic, usually straight, and 2.5 – 3.7 times as long as wide in B. purpurascens and B. glabella subsp. prostrata (Harris 2010).	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A265FFBCFF2D69E73DED5E55.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 27 ′ 20 ″ N, 062 ° 03 ′ 05 ″ W; 142 m a. s. l.; 26 Jul. 2019; habitat: xeric with polygonal patterned ground made of till and rocks, and sparse dominance of Puccinellia bruggemannii T. J. Sørensen and Stellaria longipes Goldie; QFA 0635557, CAN • same locality; 82 ° 29 ′ 09 ″ N, 062 ° 00 ′ 03 ″ W; 36 m a. s. l.; 30 Jul. 2019; habitat: mesic in a slope, with hummocks made of till and rocks, dominated by Stellaria longipes and moss; QFA 0635589. Identification. Plants 1.5 – 6.0 cm high; herbaceous; caespitose. Taproots present. Stems 1.0 – 5.5 cm long; decumbent or prostrate; hairy, with simple hairs. Leaves basal; alternate; petiolate. Petioles 2 – 4 mm long; winged; margins glabrous or ciliate, with simple hairs. Leaf blades 3 – 10 mm long, 1.1 – 2.5 mm wide; oblanceolate or obtrullate; bases attenuate; abaxial surface sparsely hairy, with simple hairs; adaxial surface glabrous; margins ciliate, with simple hairs; apices obtuse. Inflorescence a raceme, with 2 – 4 flowers; elongating as the fruit matures. Pedicels hairy. Sepals 4; 2.0 – 2.6 mm long, 1.1 – 1.5 mm wide; ovate or oblong; green or purple; surface hairy, with simple hairs; margins ciliate; apices obtuse. Petals 4; 1.3 – 3.4 mm long, 0.8 – 1.6 mm wide; obovate; unlobed; white. Androecium with 6 stamens and 0.2 – 0.4 mm long anthers. Gynoecium with 1 style and 1 stigma. Fruit a silique; 4 – 10 mm long, 2.1 – 3.7 mm wide; ovoid or spherical; purple or green; hairy, with simple hairs. Styles persisting in fruit 0.05 – 0.10 mm long, 0.3 – 0.7 mm wide. Stigmas 0.4 – 0.8 mm wide; slightly larger than the styles. Characteristics allowing to distinguish B. tho- rild-wulffii subsp. thorild-wulffii from the other Braya species on Ellesmere Island can be found under B. purpurascens.	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A265FFBCFCAF6F163BA25AEE.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 25 ′ 52 ″ N, 062 ° 07 ′ 49 ″ W; 296 m a. s. l.; 16 Jul. 2019; habitat: wetland in a mountain pass, with peat and rocks as substrates, dominated by moss and Saxifraga cernua Linnaeus; QFA 0635556. Identification. Plants 1.5 – 4.0 cm high; herbaceous; caespitose. Taproots present. Stems 1 – 3 cm long; erect or ascending; glabrous. Leaves basal and cauline; isomorphic; alternate; petiolate. Petioles 5 – 9 mm long; not winged; glabrous. Leaf blades 3 – 6 mm long, 1.5 – 4.2 mm wide; ovate; bases cuneate or obtuse; abaxial and adaxial surfaces both glabrous; margins glabrous; apices rounded or obtuse. Inflorescence a raceme, with 2 – 4 flowers; not elongating or slightly elongating as the fruit matures. Pedicels glabrous. Sepals 4; 1.8 – 2.2 mm long, 0.7 – 1.2 mm wide; ovate or oblong; green or purple, with hyaline margins; surface glabrous; margins glabrous; apices rounded or obtuse. Petals 4; 2.6 – 3.8 mm long, 0.8 – 1.4 mm wide; obovate; unlobed; not clawed; white. Androecium with 6 stamens and 0.4 – 0.5 mm long anthers. Gynoecium with 1 style and 1 stigma. Fruit a silique; 7 – 16 mm long, 0.6 – 1.1 mm wide; elongate-linear or elongateelliptic; flattened; dark purple; glabrous. Styles persist- ing in fruit 0.6 – 1.4 mm long, 0.4 – 0.5 mm wide. Stigmas 0.4 – 0.5 mm wide; as wide as the styles. Cardamine bellidifolia differs from Cardamine pole- monioides Rouy, also present on Ellesmere Island (Aiken et al. 2007), by having simple cauline leaves when present (in contrast to compound, 7 – 21 foliolate, or - pinnatisect cauline leaves; Al-Shehbaz et al. 2010 a; Saarela et al. 2020), and ≤ 7 mm long, not clawed petals (in contrast to 9.0 – 12.3 mm long, clawed petals; Saarela et al. 2020).	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A265FFBEFCAF6BE23CD75EE6.taxon	description	Figure 5 C	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A265FFBEFCAF6BE23CD75EE6.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 29 ′ 56 ″ N, 062 ° 19 ′ 19 ″ W; 48 m a. s. l.; 8 Aug. 2019; habitat: xeric near the sewage outlet, with till and rocks as substrates, and sparse dominance of Puccinellia angustata (R. Brown) E. L. Rand & Redfield and Cochlearia groenlandica; QFA 0635554 • same locality; 82 ° 31 ′ 13 ″ N, 062 ° 25 ′ 46 ″ W; 44 m a. s. l.; 27 Jul. 2019; habitat: mesic, with polygonal patterned ground made of till, dominated by Alopecurus magellanicus Lamarck and Saxifraga oppositifolia; QFA 0635555. Identification. Plants 2.5 – 6.0 cm high; herbaceous; caespitose. Taproots present. Stems 1.0 – 4.5 cm long; erect, ascending, or decumbent; glabrous. Leaves basal and cauline; heterophyllous; alternate; long-petiolate (basal leaves), short-petiolate (lower cauline leaves), and sessile (upper cauline leaves). Basal leaf petioles 8 – 13 mm long; not winged; glabrous. Basal leaf blades 4 – 6 mm long, 5 – 7 mm wide; ovate or deltate; bases truncate or subcordate; abaxial and adaxial surfaces both glabrous; margins glabrous; apices rounded or obtuse. Cauline leaf blades 3.6 – 9.0 mm long, 1.2 – 2.9 mm wide; oblanceolate; unlobed or lobed, with 1 – 2 triangular acute lobes on each side; bases cuneate. Inflorescence a raceme, with 5 – 12 flowers; elongating as the fruit matures. Pedi- cels glabrous. Sepals 4; 0.8 – 1.8 mm long, 0.4 – 0.8 mm wide; ovate or oblong; pale brown or purple, with hyaline margins; surface glabrous; margins glabrous; apices rounded or obtuse. Petals 4; 1.1 – 2.4 mm long, 0.2 – 1.0 mm wide; obovate; unlobed; white and sometimes pinkish tinged. Androecium with 6 stamens and 0.2 – 0.3 mm long anthers. Gynoecium with 1 style and 1 stigma. Fruit a silique; 3.7 – 5.9 mm long, 2.2 – 3.2 mm wide; spherical or ovoid; yellowish green or greyish purple; glabrous. Styles persisting in fruit 0.2 – 0.4 mm long, 0.1 – 0.2 mm wide. Stigmas 0.2 – 0.4 mm wide; larger than the styles.	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A267FFBEFF2D6FE53A2B5E82.taxon	description	Figure 5 D, E	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A267FFBEFF2D6FE53A2B5E82.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 26 ′ 22 ″ N, 062 ° 50 ′ 39 ″ W; 201 m a. s. l.; 7 Aug. 2019; habitat: barren ground in a slope, with till and rocks as substrates; QFA 0635552, CAN • same locality; 82 ° 31 ′ 03 ″ N, 062 ° 26 ′ 21 ″ W; 57 m a. s. l.; 26 Jun. 2019; habitat: barren ground, with polygonal patterned ground made of till and rocks, and sparse dominance of Saxifraga oppositifolia and Poa abbreviata R. Brown; QFA 0635553, CAN • same locality; 82 ° 31 ′ 35 ″ N, 062 ° 18 ′ 19 ″ W; 5 m a. s. l.; 3 Aug. 2019; habitat: wetland, with peat as substrate, dominated by Salix arctica, Saxifraga oppositifolia, and moss; QFA 0635584. Identification. Plants 2 – 4 cm high; herbaceous; caespitose. Taproots and rhizomes present. Stems 1.0 – 3.5 cm long; erect or ascending; hairy, with simple and branched hairs (2 – 5 rays: T, V, Y, cruciform, ternate, and dendritic). Leaves basal; alternate or whorled; petiolate or subsessile. Petioles 2 – 5 mm long; winged; margins ciliate, with simple hairs. Leaf blades 3 – 12 mm long, 1.4 – 3.8 mm wide; obtrullate or oblanceolate; bases attenuate; abaxial and adaxial surfaces both moderately to densely hairy, with simple and branched hairs (2 – 5 rays: Y, V, ternate, and dendritic); margins ciliate, with simple hairs; apices obtuse. Inflorescence a corymbose raceme, with 2 – 4 flowers; not elongating as the fruit matures or slightly elongating as the fruit matures. Pedicels 1.5 – 6.0 mm long; hairy. Sepals 4; 2.4 – 3.5 mm long, 1.1 – 2.1 mm wide; ovate; green or yellow, with yellow margins; surface hairy, with simple and few branched hairs (2 rays: Y and V); margins glabrous; apices obtuse or acute. Petals 4; 3.8 – 5.3 mm long; 2.0 – 2.9 mm wide; obovate; slightly lobed or undulating; yellow. Androecium with 6 stamens and 0.4 – 0.6 mm long anthers. Gynoecium with 1 style and 1 stigma. Fruit a silique; 4 – 11 mm long, 2.3 – 4.4 mm wide; ovate or lanceolate; flattened; green or purple; hairy, with simple and branched hairs (2 rays: Y, V, and T). Styles persisting in fruits 0.4 – 0.7 mm long, 0.2 – 0.4 mm wide. Stigmas 0.5 – 0.9 mm wide; distinctly larger than the styles. Among the yellow-flowered Draba species present on Ellesmere Island (D. alpina Linnaeus, D. arcto- gena (E. Ekman) E. Ekman, D. micropetala Hooker, D. oblongata R. Brown ex de Candolle, and D. pauciflora; Aiken et al. 2007; GBIF 2020), D. corymbosa and D. simmonsii Elven & Al-Shebaz are characterized by larger petals (2 – 4 mm wide; Aiken et al. 2007; Elven and Al- Shehbaz 2008; Garneau and Sabourin 2018). D. corym- bosa also has wider fruits (3.1 – 5.5 mm wide) and longer styles persisting in fruits (0.4 – 1.0 mm long) compared to D. alpina, D. micropetala, and D. simmonsii, which have 1.9 – 3.8 mm wide fruits and 0.05 – 0.30 mm long styles (Elven and Al-Shehbaz 2008; Al-Shehbaz et al. 2010 b; Garneau and Sabourin 2018). D. corymbosa has mainly branched hairs on the abaxial leaf surface, whereas the other yellow-flowered Draba species have simple or simple and branched hairs (Al-Shehbaz and Mulligan 2013; Saarela et al. 2020).	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A267FFB9FCAF6E4E3D215E3B.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 28 ′ 14 ″ N, 062 ° 51 ′ 41 ″ W; 61 m a. s. l.; 10 Jul. 2019; habitat: wetland in a mountain pass, with peat and till as substrates, dominated by Eriophorum triste (Th. Fries) Hadac & Á. Löve and moss; QFA 0635551, CAN. Identification. Plants 3.0 – 5.5 cm high; herbaceous; caespitose. Taproots present. Stems 2.0 – 4.5 cm long; erect; glabrous or hairy, with sparse branched hairs (2 – 8 rays: Y and dendritic). Leaves basal and sometimes 1 cauline; alternate or whorled; petiolate or subsessile. Petioles 2 – 3 mm long; slightly winged; margins glabrous or ciliate, with simple hairs. Basal leaf blades 4.1 – 9.0 mm long, 0.9 – 2.4 mm wide; oblanceolate; bases attenuate; abaxial surface sparsely hairy, with branched hairs (2 – 6 rays: Y, ternate, and dendritic); adaxial surface glabrous; margins ciliate with erect or deflexed, simple hairs and branched hairs (2 – 4 rays: Y and dendritic); apices acute or obtuse. Inflorescence a raceme, with 2 – 3 flowers; slightly elon- gating as the fruit matures. Pedicels 1.5 – 4.5 mm long; glabrous. Sepals 4; 1.3 – 2.6 mm long, 1.0 – 1.6 mm wide; ovate or oblong; green or purple, with hyaline margins; surface glabrous or hairy, with a few sparse simple hairs apically; margins glabrous; apices obtuse. Petals 4; 3.1 – 3.9 mm, long; 1.7 – 2.2 mm wide; obovate; unlobed or undulating; white. Androecium with 6 stamens and 0.4 – 0.6 mm long anthers. Gynoecium with 1 style and 1 stigma. Fruit a silique; 1.6 – 4.5 mm long, 1.3 – 2.7 mm wide; ovate; flattened; green or purple; glabrous. Styles persisting in fruit 0.2 – 0.7 mm long, 0.1 – 0.3 mm wide. Stigmas 0.3 – 0.5 mm wide; larger than the styles. In addition to Draba lactea, five other white-flowered Draba species are present on Ellesmere Island (D. arctica J. Vahl, D. cinerea Adams, D. fladnizensis Wulfén, D. nivalis Liljeblad, and D. subcapitata Simmons; Aiken et al. 2007; GBIF 2020). D. lactea can be differentiated by having mainly glabrous pedicels and sepals (in contrast to D. arctica, D. cinerea, D. nivalis, and D. subcapitata), and glabrous fruits (in contrast to D. arctica, D. cinerea, and D. subcapitata; Aiken et al. 2007; Garneau and Sabourin 2018). Glabrous pedicels and fruits are unique to D. fladnizensis and D. lactea, but they differ in few charac- ters: D. lactea has branched hairs (2 – 12 rays) rather than simple and 2 - forked hairs seen in D. fladnizensis (Al- Shehbaz et al. 2010 b); D. lactea has bigger petals (3 – 5 mm long, 1.8 – 3.0 mm wide) than D. fladnizensis (2.0 – 2.5 mm long, 0.8 – 1.5 mm wide; Al-Shehbaz and Mulligan 2013; Saarela et al. 2020); and margin leaf hairs of D. fladnizensis are straight and pointing strongly forward in contrast to D. lactea whose simple hairs can be deflexed and not strongly directed forward (Svalbard Flora 2020).	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A260FFB9FF2D6F313D9E584C.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 25 ′ 52 ″ N, 062 ° 07 ′ 49 ″ W; 296 m a. s. l.; 16 Jul. 2019; habitat: wetland in a mountain pass, with peat and rocks as substrates, dominated by moss and Saxifraga cernua; QFA 0635549 • same locality; 82 ° 26 ′ 34 ″ N, 062 ° 19 ′ 06 ″ W; 178 m a. s. l.; 13 Aug. 2019; habi- tat: barren ground on a river bed, with rocks as substrate; QFA 0635586, CAN. Identification. Plants 2.0 – 4.5 cm high; herbaceous; caespitose. Taproots present. Stems 1.0 – 3.5 cm long; erect or ascending; hairy, with simple and branched hairs (2 – 5 rays: T, Y, cruciform, ternate, and dendritic). Leaves basal; alternate or whorled; petiolate or subsessile. Petioles 1 – 4 mm long; winged; margins ciliate, with simple hairs. Basal leaf blades 5.7 – 8.0 mm long, 2.1 – 3.9 mm wide; obovate or oblanceolate; bases attenuate; abaxial surface moderately or densely hairy, with simple and branched hairs (2 – 4 rays: Y, ternate, cruciform, and dendritic); adaxial surface glabrous or sparsely hairy, with simple and branched hairs (2 – 3 rays: Y, and ternate); margins ciliate, with simple and branched hairs (2 rays: Y); apices obtuse. Inflorescence a raceme, with 2 – 4 flowers; elongating or not elongating as the fruit matures. Pedicels 1.0 – 4.5 mm long; hairy. Sepals 4; 2.1 – 2.4 mm long, 0.8 – 1.0 mm wide; obovate or oblong; green and purpletinged, with yellow margins; surface hairy, with simple and branched hairs (2 – 3 rays: Y and ternate); margins glabrous; apices obtuse or acute. Petals 4; 2.8 – 3.7 mm, long; 0.8 – 1.4 mm wide; oblanceolate; slightly lobed or undulating; pale yellow. Androecium with 6 stamens and 0.3 – 0.5 mm long anthers. Gynoecium with 1 style and 1 stigma. Fruit a silique; 4.0 – 9.9 mm long, 2.7 – 3.5 mm wide; oblanceolate or obovate; flattened; green; hairy, with simple hairs and branched hairs (2 rays: Y). Styles persisting in fruit 0.05 – 0.20 mm long, 0.3 – 0.5 mm wide. Stigma 0.3 – 0.5 mm wide; as wide as, or slightly larger than, the styles. Draba micropetala and D. pauciflora both have narrow petals (≤ 2 mm wide) compared to all the other yel- low-flowered Draba species on Ellesmere Island (D. alpina, D. arctogena, D. oblongata, and D. simmonsii; Aiken et al. 2007; Al-Shehbaz et al. 2010 b; GBIF 2020). In addition, pedicels are usually shorter (1 – 4 mm long) in D. micropetala than in D. alpina and D. simmonsii, which have 2.5 – 30.0 mm long pedicels (Al-Shehbaz et al. 2010 b). D. micropetala and D. pauciflora can usually be distinguished on other characters: D. micropetala has leaves with an obtuse to rounded apex, whereas D. pauciflora has leaves with an acute apex; the leaves of D. micropetala have a predominance of cruciform hairs on the leaves, whereas those of D. pauciflora have a simple and forked hairs; and D. micropetala has ovateelliptic, 2.0 – 3.2 mm wide fruits, whereas D. pauciflora has obovate, 3 – 5 mm wide fruits (Elven and Al-Shehbaz 2008; Saarela et al. 2020). The difference in the fruits did not fit exactly with our specimens from Alert. Instead, we found mainly obovate or oblanceolate, 2.7 – 3.5 mm wide fruits in D. micropetala, and lanceolate or elliptic, 1.8 – 4.0 mm wide fruits in D. pauciflora. However, based on the specimens from Alert, we found that using the dimensions of the styles and stigmas persisting on the fruits were good additional criteria to differ- entiate the two species; D. micropetala had shorter styles (0.05 – 0.20 mm long) with stigmas as wide as the styles (or very slightly wider), whereas D. pauciflora had longer styles (0.2 – 0.4 mm long) with stigmas always wider than the styles. As for the other yellow-flowered Draba found at Alert, D. corymbosa, it had even longer styles (0.4 – 0.7 mm long) and the stigmas were even more distinctly wider than the styles (the two structures appearing like a T).	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A260FFB8FCAF693C3F795DD1.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 29 ′ 58 ″ N, 062 ° 33 ′ 36 ″ W; 66 m a. s. l.; 11 Aug. 2019; habitat: mesic, with polygonal patterned ground made of till, dominated by Stellaria longipes; QFA 0635550, CAN. Identification. Plants 1.7 – 3.5 cm high; herbaceous; caespitose. Taproots present. Stems 0.4 – 3.0 cm long; erect or ascending; hairy, with simple and branched hairs (2 – 3 rays: T, V, Y, and ternate). Leaves basal; alternate or whorled; petiolate or subsessile. Petioles 2 – 5 mm long; winged; margins glabrous or ciliate, with simple hairs. Basal leaf blades 5.2 – 9.0 mm long, 1.8 – 3.4 mm wide; oblanceolate or obtrullate; bases attenuate; abaxial surface moderately hairy, with simple and branched hairs (2 – 5 rays: Y, T, ternate, and dendritic); adaxial surface sparsely to moderately hairy, with simple and branched hairs (2 rays: Y); margins ciliate, with simple long hairs; apices acute. Inflorescence a raceme, with 2 – 5 flowers; elongating or not elongating as the fruit matures. Pedicels 1.5 – 4.0 mm long; hairy. Sepals 4; 2.3 – 2.5 mm long, 0.8 – 0.9 mm wide; ovate or oblong; yellow, with hyaline margins; surface hairy, with simple and branched hairs (2 rays: Y); margins glabrous; apices obtuse. Petals 4; 2.9 – 4.0 mm long, 1.2 – 1.8 mm wide; obovate or oblanceolate; unlobed, slightly lobed, or undulating; white or pale yellow. Androecium with 6 stamens and 0.2 – 0.4 mm long anthers. Gynoecium with 1 style and 1 stigma. Fruit a silique; 5.5 – 10.0 mm long, 1.8 – 4.0 mm wide; lanceolate or elliptic; flattened; green; hairy, with simple and branched hairs (2 rays: Y, T, and V). Styles persisting in fruit 0.2 – 0.4 mm long, 0.3 – 0.5 mm wide. Stigmas 0.4 – 0.7 mm wide; larger than the styles. Characteristics allowing to distinguish D. pauciflora from the other yellow-flowered Draba species present on Ellesmere Island can be found under D. corymbosa and D. micropetala.	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A261FFBBFF2D6A973CF95BD2.taxon	description	Figure 6 A	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A261FFBBFF2D6A973CF95BD2.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 25 ′ 52 ″ N, 062 ° 07 ′ 49 ″ W; 296 m a. s. l.; 16 Jul. 2019; habitat: wetland in a mountain pass, with peat and rocks as substrates, dominated by moss and Saxifraga cernua; QFA 0635574. Identification. Plants 1 – 12 cm high; herbaceous; caespitose. Taproots and rhizomes present. Stems 2 – 12 cm long; prostrate, or ascending; hairy, with septate glandular hairs and septate non-glandular hairs. Leaves basal and cauline; opposite; subsessile (basal and lower cauline leaves) or sessile (upper cauline leaves). Basal leaf blades 5 – 12 mm long, 2 – 5 mm wide; elliptic, lanceolate, obovate, or oblanceolate; abaxial and adaxial surfaces both hairy, with septate glandular hairs and septate nonglandular hairs (hairs 1.0 – 3.4 mm long); margins ciliate; apices acute, acuminate, or obtuse. Cauline leaf blades 1.7 – 3.6 mm long, 0.5 – 1.2 mm wide; abaxial and adaxial surface both hairy; margins hyaline and ciliate. Inflores- cence a solitary flower or a dichasium, with 2 – 4 flowers. Bracts 4 – 9 mm long, 0.8 – 2.0 mm wide; surface hairy; margins hyaline (0.1 – 0.2 mm wide) and ciliate. Pedicels hairy. Sepals 5; 5.0 – 7.8 mm long, 1 – 3 mm wide; elliptic or lanceolate; green to purple; hairy, with septate glandular hairs and septate non-glandular hairs; margins hyaline and glabrous; apices acute. Petals 5; 6.0 – 9.8 mm long, 2.7 – 4.0 mm wide; obtriangular or oblanceolate; notched; white. Androecium with 10 stamens and 0.9 – 1.5 mm long, yellow anthers. Gynoecium with 5 styles and 1 stigma per style. Fruit a capsule; 9 – 11 mm long, 3 – 5 mm wide; cylindrical; straw-colored; ending with 8 – 10 teeth; glabrous. Cerastium Linnaeus species can be differentiated from Arenaria Linnaeus and Stellaria Linnaeus species by the petals: Cerastium species have petals cleft at most to 25 %, whereas Arenaria species have unlobed petals and Stellaria species have petals cleft nearly to the base (Aiken et al. 2007). C. arcticum is very similar to C. alpinum Linnaeus subsp. alpinum and subsp. lanatum (Lamarck) Cesati, C. beeringianum Chamisso & Schlechtendal, and C. bialynickii Tolmatchew that are present on Ellesmere Island (GBIF 2020), but a few characters help differentiate them. C. arcticum has leaves with hairs that are always> 0.3 mm long, whereas both C. alpinum subspecies have long but also short hairs (<0.3 mm long); bracts have more distinct hyaline margins in both C. alpinum subspecies (0.3 – 0.8 mm wide) than in C. arcticum (≤ 0.3 mm wide; Blondeau 2015 a). As for the differences between C. beeringianum and C. arcticum, hairs on leaves are longer in C. arcticum (≥ 0.9 mm long) than in C. beeringianum (≤ 0.9 mm long); bract leaves of C. arcticum (4 – 9 mm long) are longer than those of C. beeringianum (2.5 – 3.0 mm long); and fruits of C. arcticum are also larger (3 – 5 mm wide) than those of C. beeringianum (2 – 3 mm wide; Aiken et al. 2007; Blondeau 2015 a). C. bialynickii has a pulvinate growth form with short stems (1 – 10 cm long), whereas C. arcticum, both C. alpinum subspecies, and C. beeringianum have rhizomatous or mat-forming, not pulvinate growth form (cushion-like) with longer stems (5 – 50 cm long; Morton 2005). The stem length of the specimens of C. arcticum from Alert ranges from 2 to 12 cm and some specimens had a cushion growth form rather than a mat-forming growth form, and therefore do not exactly match the criteria above. Although, C. bialynickii is considered a synonym of C. beeringianum in Aiken et al. (2007), it is treated as a distinct species in FNA (Flora of North America Editorial Committee 2005), Tropicos (2020), and VASCAN (Brouillet et al. 2010 +; Desmet and Brouillet 2013).	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A261FFB8FF2D6C9A3FD35BD4.taxon	description	Figure 5 F	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A261FFB8FF2D6C9A3FD35BD4.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 28 ′ 51 ″ N, 062 ° 10 ′ 58 ″ W; 86 m a. s. l.; 15 Aug. 2019; habitat: xeric, with till and rocks as substrate, and sparse dominance of Saxifraga oppositifolia; QFA 0635585, CAN. Identification. Plants 1 – 2 cm high; herbaceous; caespitose. Taproots present. Stems 0.5 – 1.5 cm long; erect or ascending; hairy, with simple and branched hairs (2 – 4 rays: T, V, and dendritic). Leaves basal; alternate or whorled; petiolate or subsessile. Petioles 1.0 – 1.5 mm long; slightly winged; margins glabrous or ciliate, with simple hairs. Basal leaf blades 3.7 – 5.0 mm long, 1 – 2 mm wide; linear or narrowly obtrullate; bases attenuate; midvein prominent; abaxial surface glabrous or sparsely hairy, with simple and branched hairs (2 rays: Y and T); adaxial surface glabrous; margins slightly revolute and ciliate, with simple long hairs; apices acute or obtuse. Inflorescence a raceme, with 2 or 3 flowers; not or slightly elongating as the fruit matures. Pedicels 1 – 2 mm long; hairy. Sepals 4; 1.2 – 1.6 mm long, 0.7 – 0.8 mm wide; ovate or oblong; green or purple, with hyaline margins; surface hairy, with simple hairs; margins glabrous; apices obtuse. Petals 4; 1.3 – 2.2 mm, long; 0.8 – 1.1 mm wide; obovate; unlobed, slightly lobed, or undulating; white. Androecium with 6 stamens and 0.3 – 0.4 mm long anthers. Gynoecium with 1 style and 1 stigma. Fruit a silique; 3 – 5 mm long, 2.0 – 2.3 mm wide; ovate or elliptic; slightly bulged; dark purple; glabrous or sparsely hairy, with simple hairs. Styles persisting in fruit 0.05 – 0.30 mm long, 0.2 – 0.3 mm wide. Stigmas 0.2 – 0.3 mm wide; as wide as the styles. Draba subcapitata differs from the five other whiteflowered Draba species present on Ellesmere Island (Aiken et al. 2007; GBIF 2020) by having smaller petals (≤ 2.5 mm long and ≤ 1.0 mm wide; in contrast to D. arctica, D. cinerea, D. fladnizensis, D. lactea, D. nivalis; Aiken et al. 2007), and by the combination of predominantly simple and branched hairs (2 – 4 rays) on leaves and stems (in contrast to the presence of hairs with> 4 rays in D. arctica, D. lactea, and D. nivalis; Garneau and Sabourin 2018). Caryophyllaceae – Pink family	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A262FFBAFF2D6A993CD05F96.taxon	description	Figure 6 B, C	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A262FFBAFF2D6A993CD05F96.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 29 ′ 09 ″ N, 062 ° 00 ′ 03 ″ W; 36 m a. s. l.; 30 Jul. 2019; habitat: mesic in a slope, with hummocks made of till and rocks, dominated by Stellaria longipes and moss; QFA 0635520 • same locality; 82 ° 26 ′ 48 ″ N, 062 ° 26 ′ 12 ″ W; 178 m a. s. l.; 28 Jul. 2019; habitat: wetland, with peat and rocks as substrates, dominated by Alopecu- rus magellanicus and moss; QFA 0635576. Identification. Plants 1 – 5 cm high; herbaceous; caespitose. Taproots and rhizomes present. Stems 1 – 4 cm long; prostrate, decumbent, or ascending; hairy, with septate non-glandular hairs. Axillary branches present. Leaves basal and cauline; isomorphic; opposite; petiolate (basal leaves) or sessile (cauline leaves). Petiole 1.4 – 2.0 mm long; hairy. Basal leaf blades 3 – 6 mm long, 1.8 – 3.0 mm wide; elliptic or ovate; abaxial and adaxial surfaces both glabrous; margins glabrous or ciliate, with septate nonglandular hairs; apices obtuse. Cauline leaf blades 2.8 – 4.8 long, 0.5 – 1.7 mm; abaxial and adaxial surfaces both glabrous; margins ciliate, with septate non-glandular hairs; apices obtuse. Inflorescence a solitary flower or a dichasium with 2 flowers. Bracts 2 – 4 mm long, 1 – 2 mm wide; surface hairy; margins hyaline (≤ 0.1 mm wide) and ciliate. Pedicels hairy. Sepals 5; 4 – 5 mm long, 1 – 3 mm wide; lanceolate or elliptic; green and purple-tinged, with hyaline margins; surface hairy, with septate nonglandular hairs and spetate-glandular hairs; margins ciliate; apices acute. Petals 5; 5.1 – 8.0 mm long, 2.3 – 5.0 mm wide; obtriangular, oblanceolate, or obovate; notched; white. Androecium with 7 – 10 stamens and 0.6 – 1.2 mm long, pale yellow anthers. Gynoecium with 5 styles and 1 stigma per style. Fruit a capsule; 8.0 – 10.4 mm long, 2 – 3 mm wide; cylindrical; straw-colored; ending with 8 – 10 teeth; glabrous. Cerastium regelii differs from C. alpinum, C. arcticum, C. beeringianum, and C. bialynickii by having shiny, glabrous leaf surfaces, whereas the four latter species have dull, densely hairy leaves (Aiken et al. 2007).	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A263FFBAFF2D69543C695459.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 27 ′ 34 ″ N, 062 ° 44 ′ 57 ″ W; 118 m a. s. l.; 16 Aug. 2019; habitat: xeric, with polygonal patterned ground made of till and rocks, and sparse dominance of Juncus biglumis Linnaeus and moss; QFA 0635571. Identification. Plants 1 – 3 cm high; herbaceous; caespitose. Taproots present. Stems 0.5 – 1.5 cm long; prostrate, decumbent, or ascending; glabrous. Leaves cauline; opposite; sessile. Leaf blades 2 – 3 mm long, 0.3 – 1.0 mm wide; elliptic or linear; upwardly curved; appearing single-veined or veins inconspicuous; green, dark purple, or dark red; abaxial and adaxial surfaces both glabrous; margins glabrous; apices obtuse. Inflorescence a solitary flower. Pedicels glabrous. Sepals 5; 1.0 – 2.8 mm long, 0.5 – 1.3 mm wide; ovate; purple; surface glabrous; margins glabrous; apices obtuse or acute. Petals 5; 2 – 3 mm long, 0.7 – 1.2 mm wide; oblong or obovate; unlobed; white. Androecium with 10 stamens and 0.4 – 0.5 mm long, yellow anthers. Gynoecium with 3 styles and 1 stigma per style. The only two Sabulina Reichenbach species present on Ellesmere have been found in our survey (Aiken et al. 2007; GBIF 2020). They differ in a few characters: S. rossii has glabrous stems, whereas S. rubella has pubescent stems with glandular hairs (Blondeau et al. 2015 b; Saarela et al. 2020), and S. rossii has single-veined (if vein apparent) leaf blades, whereas S. rubella has threeveined leaf blades (Aiken et al. 2007).	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A263FFBAFCAF6DC23A8D5843.taxon	description	Figure 6 D	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A263FFBAFCAF6DC23A8D5843.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 26 ′ 22 ″ N, 062 ° 50 ′ 39 ″ W; 201 m a. s. l.; 7 Aug. 2019; habitat: barren ground in a slope, with till and rocks as substrates; QFA 0635573. Identification. Plants 1.5 – 3.5 cm high; herbaceous; caespitose. Taproots present. Stems 0.8 – 2.5 cm long; prostrate, decumbent, or ascending; hairy, with glandular hairs. Leaves cauline; opposite; sessile. Leaf blades 3.0 – 5.7 mm long, 0.5 – 1.0 mm wide; lanceolate or linear; straight or acending; veins 3; green; abaxial and adaxial surfaces both glabrous; margins ciliate, with glandular hairs; apices acute or apiculate. Inflorescence a solitary flower. Pedicels hairy. Sepals 5; 2 – 3 mm long, 0.5 – 1.4 mm wide; lanceolate; purple or green, with hyaline margins; surface glabrous or hairy, with glandular hairs; margins glabrous; apices acute. Petals 5; 2 – 3 mm long, 1.0 – 1.5 mm wide; oblanceolate or obovate; unlobed; white. Androecium with 10 stamens and 0.2 – 0.3 mm long, yellow anthers. Gynoecium with 3 styles and 1 stigma per style. Fruit a capsule; 2.8 – 3.0 mm long, 1.4 – 1.6 mm wide; ovoid or conical; straw-colored; glabrous. Characteristics allowing to distinguish S. rubella from the other Sabulina species present on Ellesmere Island can be found under S. rossii.	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A263FFA5FCAF69083F525DB7.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 28 ′ 35 ″ N, 062 ° 28 ′ 23 ″ W; 117 m a. s. l.; 15 Jul. 2019; habitat: xeric on a plateau between two creeks, with till and rocks as substrates; QFA 0635570. Identification. Plants 3 – 5 cm high; herbaceous; not caespitose. Taproots present. Stems 1.5 – 3.5 cm long; erect; hairy, with septate non-glandular hairs. Leaves basal and cauline; opposite; petiolate (basal and lower cauline leaves) or sessile (upper cauline leaves). Petioles 3 – 5 mm long; glabrous. Basal leaf blades 5 – 11 mm long, 1 – 3 mm wide; obtrullate or oblanceolate; green or purple; abaxial and adaxial surfaces both glabrous; margins ciliate, with sparse hyaline, septate non-glandular hairs; apices acute. Cauline leaf blades 6 – 9 mm long, 1 – 2 mm wide; abaxial and adaxial surfaces both sparsely hairy, with septate non-glandular hairs; margins ciliates; apices acute. Inflorescence a solitary flower. Bracts 3 – 4 mm long, 0.8 – 2.0 mm wide. Pedicels hairy. Sepals 5; fused. Calyx bell-shaped; 9 – 15 mm long, 7 – 11 mm wide; 5 - lobed; hyaline, whitish purple or pink, with dark purple longitudinal ribs; hairy, with septate non-glandular hairs. Petals 5; same length or slightly longer than the calyx (emerging of 1.2 – 2.5 mm long from the calyx); oblanceolate; notched; pinkish purple. Androecium with 8 – 10 stamens and 0.6 – 0.8 mm long, greenish-yellow anthers. Gynoecium with 5 styles and 1 stigma per style. Silene uralensis subsp. uralensis differs from the three other Silene species present on Ellesmere Island (S. acaulis (Linnaeus) Jacquin, S. involucrata (Chamisso & Schlechtendal) Bocquet subsp. involucrata and subsp. tenella (Tolmachew) Bocquet, and S. sorensenis (B. Boivin) Bocquet; Aiken et al. 2007; GBIF 2020) by having petals of the same length as the calyx or slightly longer; the others have petals largely exceeding the calyx (Aiken et al. 2007).	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A27CFFA5FF2D6BE33D445F89.taxon	materials_examined	Syn.: Carex aquatilis subsp. stans (Drejer) Hultén Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 28 ′ 57 ″ N, 062 ° 38 ′ 31 ″ W; 22 m a. s. l.; 5 Aug. 2019; habitat: wetland on the margins of a river delta, with peat as substrates, dominated by Eriophorum triste and moss; QFA 0635568 • same locality; 82 ° 30 ′ 08 ″ N, 062 ° 52 ′ 60 ″ W; 91 m a. s. l.; 2 Aug. 2019; habi- tat: wetland in a mountain pass on the margins of a pond, with tussocks made of peat, dominated by Eriophorum triste; QFA 0635569. Identification. Plants 5 – 9 cm high; herbaceous; not caespitose. Fibrous roots and rhizomes present. Stems 2.5 – 11.0 cm long; erect, ascending, or decumbent; scabrous on angles. Leaves basal and cauline; alternate. Sheath margins glabrous. Ligules 0.6 – 2.0 mm long. Basal leaf blades 35 – 75 mm long, 1.8 – 4.0 mm wide; linear; flat or folded; abaxial and adaxial surfaces both gla- brous; margins scabrous. Inflorescence a raceme, with 2 – 6 spikelets; 19 – 40 mm long. Bracts exceeding the inflorescence; 28 – 50 mm long. Lateral spikelets unisexual; pistillate; pedunculate; erect. Terminal spikelets unisexual; staminate; erect; pedunculate. Pistillate scales 1.1 – 2.8 mm long, 0.6 – 1.5 mm wide; ovate; purple or purplish brown, with midvein paler in color or pale green; apices acute. Staminate scales 2.0 – 2.8 mm long, 0.5 – 1.0 mm wide; oblanceolate; purple, with midvein paler in color; apices acuminate. Perigynium 1.1 – 2.5 mm long, 0.6 – 1.8 mm wide; ovate or obovate; flattened; green or pale brown proximally and purplish-brown apically; surface glabrous; margins glabrous; apices beaked. Androecium with 3 stamens and 1.8 – 2.8 mm long anthers. Gynoecium with 1 style and 2 stigmas.	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A27CFFA5FF2D6BE33D445F89.taxon	description	Carex aquatilis var. minor differs from all other Carex Linnaeus species on Ellesmere Island by having the lower bract exceeding the inflorescence (Aiken et al. 2007).	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A27CFFA5FF2D6CB53FFA5AE8.taxon	description	Figure 6 F, G	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A27CFFA5FF2D6CB53FFA5AE8.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 29 ′ 59 ″ N, 062 ° 27 ′ 56 ″ W; 82 m a. s. l.; 27 Jul. 2019; habitat: xeric in a slope, with polygonal patterned ground made of till and rocks, and sparse dominance of Saxifraga oppositifolia; QFA 0635575. Identification. Plants 1 – 8 cm high; herbaceous; caespitose. Taproots and thin rhizomes present. Stems 2 – 8 cm long; prostrate, decumbent, or erect; glabrous. Axillary branches present. Leaves cauline; opposite; sessile. Cauline leaf blades 4 – 9 mm long, 1.1 – 3.0 mm wide; lanceolate; appearing single-veined (midrib prominent); abaxial surface keeled; abaxial and adaxial surfaces both glabrous; margins glabrous; apices acute or acuminate. Inflorescence a solitary flower or a dichasium, with 2 flowers. Bracts 2.2 – 7.0 mm long, 0.6 – 2.0 mm wide. Ped- icels glabrous. Sepals 5; 2 – 4 mm long, 1.0 – 1.5 mm wide; lanceolate; green, with hyaline margins; surface; margins ciliate; apices acute. Petals 5; 3 – 5 mm long, 3 – 4 mm wide; obovate or obtriangular; deeply cleft; white. Androecium with 8 – 10 stamens and 0.6 – 0.8 mm long, red anthers. Gynoecium with 3 styles and 1 stigma per style. The deeply cleft petals distinguish Stellaria species from the other Caryophyllaceae genus (Aiken et al. 2007). S. longipes subsp. longipes can be differenti- ated from the two other Stellaria species on present on Ellesmere Island (GBIF 2020) by the following: S. lon- gipes has red anthers, whereas S. humifusa Rottbøll and S. crassifolia Ehrhart have yellow anthers (Aiken et al. 2007); and S. longipes has strongly keeled leaf blades with midvein prominent, whereas S. humifusa and S. crassifolia have flat leaf blades with midvein obscure (Saarela et al. 2020). Cyperaceae – Sedge family	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A27CFFA4FCAF69423C7B5F07.taxon	description	Figure 7 A	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A27CFFA4FCAF69423C7B5F07.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 30 ′ 25 ″ N, 062 ° 36 ′ 45 ″ W; 24 m a. s. l.; 8 Aug. 2019; habitat: wetland on the margins of a small river, with peat and till as substrates, dominated by Alopecurus magellanicus and moss; QFA 0635566 • same locality; 82 ° 27 ′ 37 ″ N, 062 ° 51 ′ 53 ″ W; 16 m a. s. l.; 20 Jul. 2019; habitat: wetland on the margins of a lake, with peat and till as substrates, dominated by moss, Eriophorum scheuchzeri, and Eriophorum triste; QFA 0635567. Identification. Plants 4 – 13 cm high; herbaceous; caespitose. Fibrous roots present. Stems 3.5 – 11.5 cm long; erect or ascending; glabrous. Leaves basal and cauline; alternate. Sheath margins scabrous. Ligule absent or inconspicuous. Basal leaf blades 20 – 45 mm long, 2 – 4 mm wide; linear; flat or folded; curled; abaxial and adaxial surfaces both glabrous; margins scabrous. Inflorescence a raceme, with 2 – 4 spikelets; 12 – 40 mm long. Bracts shorter than the inflorescence; 8 – 32 mm long. Lateral spikelets pistillate or sometimes gynecandrous; pedunculate; inclined or pendent. Terminal spikelets bisexual; gynecandrous; pedunculate; inclined. Pistillate scales 2.5 – 4.0 mm long, 0.8 – 1.5 mm wide; lanceolate; purplish brown, with hyaline margins or paler in color (sometimes midvein paler in color); apices acute or acuminate. Staminate scales 3.2 – 3.6 mm long, 0.8 – 1.3 mm wide; oblanceolate; pinkish purple or brownish purple, with hyaline margins; apices acute or acuminate. Perigynium 3.0 – 4.5 mm long, 0.7 – 1.4 mm wide; pyriform or lanceoloid; green or pale brown proximally and dark purple apically; surface glabrous; margins scabrous; apices beaked, bidentate. Androecium with 3 stamens and 1.8 – 2.4 mm long anthers. Gynoecium with 1 style and 3 stigmas. Among the 12 Carex species present on Ellesmere Island with compound spikes (GBIF 2020), Carex fuliginosa can be differentiated by the following: pedunculate and mostly unisexual spikelets (in contrast to C. marina Dewey and C. maritima Gunnerus with only bisexual, sessile spikelets); terminal gynaecandrous spikelet (in contrast to terminal staminate spikelet in C. atrofusca Schkuhr, C. capillaris Linnaeus subsp. fuscidula (V. I. Kreczetovicz ex T. V. Egorova) Á. Löve & D. Löve, C. glacialis Mackenzie, and C. membranacea Hooker); 2.5 – 5.0 mm long pistillate scales (in contrast to C. krausei Boeckeler with 1.6 – 2.1 mm long pistillate scales); fused perigynum margins (in contrast to open perigynum margins in C. simpliciuscula Wahlenberg); and three stigmas (in contrast to two stigmas in C. aquatilis var. minor, C. bigelowii Torrey ex Schweinitz subsp. bigelowii, and C. saxatilis Linnaeus; Saarela et al. 2020).	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A27DFFA4FF2D6EC43A4E5E74.taxon	description	Figure 7 B	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A27DFFA4FF2D6EC43A4E5E74.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 27 ′ 37 ″ N, 062 ° 51 ′ 53 ″ W; 16 m a. s. l.; 20 Jul. 2019; habitat: wetland on the margins of a lake, with peat and till as substrates, dominated by moss, Eriophorum scheuchzeri, and Eriophorum triste; QFA 0635564. Identification. Plants 8 – 13 cm high; herbaceous; not caespitose. Fibrous roots and rhizomes present. Stems 6.5 – 11.0 cm long; erect; glabrous. Leaves basal and cauline; alternate. Sheath margins glabrous. Ligules 0.5 – 3.1 mm long. Basal leaf blades 20 – 65 mm long, 0.5 – 2.0 mm wide; linear; folded; straight; abaxial and adaxial surfaces both glabrous; margins glabrous. Cauline bladeless leaves with sheaths brown apically and hyaline margins. Inflorescence a spike; 15 – 30 mm long. Bract absent. Spikelet spherical; bisexual, with both sexes in each floret; sessile. Proximal scales (4 – 6 empty scales proximally); 3.0 – 6.3 mm long, 1 – 4 mm wide; ovate or lanceolate; grey or black, with hyaline margins; apices acute. Perianth represented by bristles; bright white. Androecium with 3 stamens and 0.5 – 1.5 mm long anthers. Gynoecium with 1 style and 3 stigmas. Fruit an achene; 1.5 – 2.2 mm long, 0.6 – 0.9 mm wide; obovoid or lanceoloid; glabrous. Four Eriophorum Linnaeus species are present on Ellesmere Island (GBIF 2020). Only E. triste and E. angustifolium Honckeny subsp. angustifolium have more than two spikelets, whereas E. scheuchzeri and E. callitrix Chamisso have a solitary spikelet (Saarela et al. 2020). E. scheuchzeri differs by having rhizomes and ≤ 7 empty proximal scales, whereas E. callitrix is caespitose (i. e., without rhizomes) and has usually ≥ 10 empty proximal scales (Saarela et al. 2020). In addition, two subspecies of E. scheuchzeri are found on Ellesmere Island (GBIF 2020) and can be differentiated according to the following characters: subsp. arcticum has spherical spikelets, whereas subsp. scheuchzeri has hemispherical spikelets; proximal fertile scales of subsp. arcticum are darker and gradually passing to paler grey tones with conspicuous hyaline margins, whereas proximal fertile scales of subsp. scheuchzeri are completely dark with dark margins or reduced, sharply differentiated hyaline margins (Saarela et al. 2020).	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A27DFFA7FCAF6F773C295AE0.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 27 ′ 37 ″ N, 062 ° 51 ′ 53 ″ W; 16 m a. s. l.; 20 Jul. 2019; habitat: wetland on the margins of a lake, with peat and till as substrates, dominated by moss, Eriophorum scheuchzeri, and Eriophorum triste; QFA 0635565. Identification. Plants 8 – 19 cm high; herbaceous; not caespitose. Fibrous roots and rhizomes present. Stems 7.0 – 16.5 cm long; erect; glabrous. Leaves basal and cauline; alternate. Sheath margins scabrous. Ligules 0.6 – 1.7 mm long. Basal leaf blades 30 – 90 mm long, 1.3 – 4.0 mm wide; linear; flat or folded; straight; abaxial surface sca- brous; adaxial surface glabrous; margins scabrous. Inflo- rescence a raceme, with 2 – 4 spikelets; 15 – 30 mm long. Lower bracts shorter than the inflorescence; 13 – 24 mm long. Peduncles 5 – 18 mm long; scabrous all around the surface. Lateral spikelets and terminal spikelet bisexual, with both sexes in each floret; pedunculate; erect or pendent. Proximal scales 3.8 – 5.3 mm long, 2.0 – 3.1 mm wide; ovate or lanceolate; greyish black sometimes purple or red-tinged, with or without narrow, hyaline margins at the apex; apices acute or acuminate. Perianth represented by bristles; white or yellowish-brown. Androecium with 3 stamens and 1.9 – 3.8 mm long anthers. Gynoecium with 1 style and 3 stigmas. Fruit an achene; 2.0 – 2.4 mm long, 0.9 – 1.9 mm wide; obovoid; keeled; glabrous. Eriophorum triste is similar to E. angustifolium subsp. angustifolium by having more than two spikelets, but can be differentiated by culms, peduncles, scale, and anther characters: E. triste has shorter culms (≤ 30 cm) than E. angustifolium (20 – 100 cm; Ball and Wujek 2002); E. triste has scabrous, arcuate, ≤ 2 cm peduncles, whereas E. angustifolium has glabrous (or scabrous on angles), drooping, ≤ 10 cm long peduncles (Ball and Wujek 2002; Saarela et al. 2020); E. triste has grey to black scales with or without hyaline margins, whereas E. angustifolium has brownish grey, greyish, reddish or ferruginous scales with broad hyaline margins (Ball and Wujek 2002; Saarela et al. 2020); anthers of E. triste are usually shorter (1.8 – 3.0 mm long) than those of E. angustifolium (2.5 – 5.0 mm long; Saarela et al. 2020); and fruits are obovoid, 2.0 – 2.5 mm long in E. triste, whereas they are oblong-obovoid or oblong-elliptical, 2.5 – 3.5 mm long in E. angustifolium (Saarela et al. 2020). The culm height from the specimens of Alert (9 – 16 cm), as well as the peduncle length and scabrousity, and the fruit dimensions and shape correspond with those reported in the literature, but not the scale color and the anther length. The scales were not only grey to black, but some scales also had a reddish-purple tinge in the center. The anthers were also longer than the maximum anther length known in E triste. Only E. triste has previously been found at Alert and the surrounding areas (GBIF 2020). Equisetaceae – Horsetail family	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A27EFFA6FF2D6BEB3F825E9D.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 28 ′ 22 ″ N, 062 ° 36 ′ 20 ″ W; 78 m a. s. l.; 17 Jul. 2019; habitat: xeric on the margins of a river inside a creek; QFA 0634994. Identification. Plants 2 – 7 cm high; herbaceous; not caespitose. Fibrous roots and rhizomes present. Rhizomes black or reddish-brown. Vegetative stems 2 – 7 cm long; annual; ascending or decumbent; green or yellowish-green; simple or branched from the whorls (branches ascending). Leaves reduced to fused sheaths in whorls. Cauline sheaths 0.5 – 2.0 mm long; yellowish-green proximally and purplish-brown apically, and sometimes with hyaline margins; ending with 4 – 8 teeth. Cauline teeth lanceolate; apices acute. Rameal sheaths 0.3 – 0.8 mm long; attenuate; green and sometimes brown apically; ending with 3 or 4 teeth. Teeth triangular or lanceolate; apices acute. Sporiferous stems annual; erect; green or yellowish-green; simple. Strobilus 4.5 mm long, 2 mm wide. Three Equisetum Linnaeus species are present on Ellesmere Island, although E. pratense Ehrhart has only been found once near Eureka (GBIF 2020). Equisetum arvense and E. pratense both have vegetative stems bearing whorls of branches, whereas the vegetative stems are unbranched in E. variegatum (Hauke 1993). Equisetum arvense has ascending branches with attenuate, rameal sheath teeth, whereas E. pratense has spreading branches with deltate, rameal sheath teeth (Hauke 1993). Equisetum variegatum Schleicher ex F. Weber & D. Mohr subsp. variegatum Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 30 ′ 25 ″ N, 062 ° 36 ′ 45 ″ W; 24 m a. s. l.; 8 Aug. 2019; habitat: wetland on the margins of a small river, with peat and till as substrates, dominated by Alo- pecurus magellanicus and moss; QFA 0634993. Identification. Plants 2 – 10 cm high; herbaceous; not caespitose. Fibrous roots and rhizomes present. Rhizomes black, purplish brown, or orange. Vegetative stems 2.5 – 9.0 cm long; evergreen; ascending or decumbent; green or yellowish-green; simple. Leaves reduced to fused sheaths in whorls. Cauline sheaths 1 – 3 mm long; green or yellowish-green proximally, with an apical broad black band, and white margins; ending with 4 – 8 teeth. Teeth triangular or lanceolate; apices acute or awned. Sporiferous stems not seen at Alert. Characteristics allowing to distinguish E. variegatum from the other Equisetum species present on Ellesmere Island can be found under E. arvense. Juncacea – Rush family	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A27FFFA6FF2D6E4E3D215459.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 27 ′ 17 ″ N, 062 ° 35 ′ 55 ″ W; 166 m a. s. l.; 11 Jul. 2019; habitat: mesic in a slope; QFA 0635561 • same locality; 82 ° 29 ′ 09 ″ N, 062 ° 00 ′ 03 ″ W; 36 m a. s. l.; 30 Jul. 2019; habitat: mesic in a slope, with hummocks made of till and rocks, dominated by Stellaria longipes and moss; QFA 0635562. Identification. Plants 2 – 8 cm high; herbaceous; caespitose or not caespitose. Fibrous roots and short rhizomes present. Stems 1.0 – 7.5 cm long; erect; glabrous. Leaves basal. Sheaths hyaline or pale reddish-brown; margins glabrous. Basal leaf blades 16 – 40 mm long, 0.6 – 1.2 mm wide; linear; canaliculate or folded; green or purple; abaxial and adaxial surfaces both glabrous; margins glabrous; apices acuminate, sometime calloused, and black or dark purple. Inflorescence an anthela, with 1 or 2 flow- ers inserted on top of the other; 5.7 – 8.0 mm long. Bracts 5.0 – 8.7 mm long; exceeding the inflorescence; spathi- form; green or reddish-purple; margins glabrous; apices acute and calloused. Bracteoles absent. Tepals 6; 2.1 – 3.9 mm long; 0.6 – 0.8 mm wide; lanceolate, oblong, or oblanceolate; purple; margins hyaline; apices obtuse. Androecium with 6 stamens and 0.5 – 0.8 mm long anthers. Gynoecium with 3 styles and 1 stigma per style. Fruit a capsule; 2.9 – 4.0 mm long, 1.3 – 1.9 mm wide; obvoid; trilocular; purple or reddish-brown, with dark purplish valve margins; glabrous. Juncus biglumis can be separated from the three other Juncus Linnaeus species present on Ellesmere Island (Aiken et al. 2007; GBIF 2020) by the following characters: flowers of J. biglumis are side by side in a vertical plane, in contrast to J. arcticus Willdenow, J. castaneus Smith subsp. leucochlamys (W. J. Zinger ex V. I. Kreczetowicz) Hultén, and J. triglumis Linnaeus subsp. albescens (Lange) Hultén, which have flowers ordered side by side in a horizontal plane; and anthers of J. biglumis (0.4 – 0.7 mm long) are smaller than the other species (≥ 0.7 mm long in J. arcticus, J. castaneus, and J. triglumis; Aiken et al. 2007).	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A27FFFA6FCAF6DC23A99592D.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 28 ′ 24 ″ N, 062 ° 14 ′ 38 ″ W; 109 m a. s. l.; 18 Jul. 2019; habitat: mesic on the margins of a river active during spring snowmelt; QFA 0635563. Identification. Plants 4 – 14 cm high; herbaceous; caespitose or not caespitose. Fibrous roots and short rhizomes present. Stems 3.0 – 12.5 cm long; erect; glabrous. Leaves basal and cauline. Sheaths brown or straw-colored; margins glabrous. Basal leaf blades 18 – 55 mm long, 0.8 – 4.0 mm wide; linear; flat; green and pale orange; abaxial and adaxial surfaces both glabrous; margins hairy, with nonglandular hairs; apices mucronulate or acute, calloused, and dark purple. Cauline leaf blades 12 – 20 mm long, 0.6 – 1.5 mm wide; folded or involute. Inflorescence an anthela, with 1 – 4 glomerules and ≤ 60 flowers; 6 – 13 mm long. Bracts 4 – 12 mm long; not exceeding the inflorescence; lanceolate; red; margins glabrous; apices acute or acuminate. Bracteoles 2; 1.5 – 2.5 mm long. Tepals 6; 0.8 – 1.7 mm long, 0.6 – 0.8 mm wide; ovate; dark brown or dark purple; margins hyaline; apices acute or obtuse. Androecium with 6 stamens and 0.3 – 0.5 mm long anthers. Gynoecium with 3 styles and 1 stigma per style. Fruit a capsule; 1.9 – 2.5 mm long, 1.0 – 1.4 mm wide; ovoid; slightly flattened; green to dark purple; with a small beak; glabrous. Luzula nivalis is similar to L. confusa Lindeberg, also present on Ellesmere Island, but the two differ in the fol- lowing characters: L. nivalis has narrow, flat basal leaves (≤ 5 cm long, 2 – 4 mm wide), whereas L. confusa has larger, subcanaliculate to flat leaves (6 – 9 cm long, 1.5 – 2.5 mm wide; Saarela et al. 2020); L. nivalis has leaves with calloused tip but not L. confusa (Hay 2013); and L. nivalis has mucronulate leaf apices, whereas L. confusa has acuminate apices (Saarela et al. 2020). Orobanchaceae – Broomrape family	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A27FFFA1FCAF68DE3FCD5956.taxon	description	Figure 8	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A27FFFA1FCAF68DE3FCD5956.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 31 ′ 04 ″ N, 062 ° 28 ′ 48 ″ W; 66 m a. s. l.; 27 Jul. 2019; habitat: mesic, with hummocks made of till, dominated by Stellaria longipes, Saxifraga oppositifolia, and moss; QFA 0635577. Identification. Plants 4 – 9 cm high; herbaceous; not caespitose. Taproots present. Stems 2 – 7 cm long; erect; hairy, with woolly hairs; with cataphylls. Leaves basal and cauline; heterophyllous; alternate; petiolate (basal and lower cauline leaves) or sessile (upper cauline leaves). Petioles 5 – 15 mm long; winged (basal leaves) or not winged (some cauline leaves); hairy, with floccose white hairs. Basal leaf blades 4 – 17 mm long, 3 – 5 mm wide; elongateoblong; pinnatifid or pinnatisect, with 5 – 8 crenate lobes on each side; green to purple; abaxial and adaxial surfaces both sparsely to moderately hairy, with floccose hairs. Cauline leaf blades 3 – 7 mm long, 1 – 3 mm wide. Inflorescence a spiciform raceme, with 10 – 16 flowers. Bracts floccose. Pedicels hairy. Flowers zygomorphic. Sepals 5; fused. Calyx tubular; 2.5 – 6.0 mm long, 2 – 4 mm wide; with 5 lobes apically; purple; surface hairy, with floccose hairs; margins ciliate; apices obtuse. Pet- als 5; fused; white and pink. Corolla bilabiate; 6 – 13 mm long with an inferior 2 - or 3 - lobed lip, and a superior narrow galeate lip. Galeate lip with 2 small teeth apically. Androecium with 4 stamens and 1.0 – 1.4 mm long anthers. Gynoecium with 1 style and 1 stigma. Stamens and stigma not protruding from the corolla tube. Pedicularis hirsuta can be differentiated from the four other Pedicularis Linnaeus species present on Ellesmere Island (Aiken et al. 2007; GBIF 2020) by the following: leaves distributed along the stem (in contrast to mainly scapose stems in P. sudetica Willdenow subsp. albola- biata Hultén and subsp. arctoeuropaea Hultén; Aiken et al. 2007; Saarela et al. 2020); floccose hairs on stems and petioles (in contrast to glabrous stems and petioles in P. sudetica; Aiken et al. 2007); basal leaf blades with 5 – 11 lobes on each side (in contrast to 10 – 25 lobes in P. lanata Willdenow ex Chamisso & Schlechtendal subsp. lanata and P. sudetica; Aiken et al. 2007; Garneau 2018); pink, purple or white petals (in contrast to yellow petals present in P. capitata Adams; Aiken et al. 2007; Saarela et al. 2020); style hidden inside galea (in contrast to style protruding in P. langsdorffii Fischer ex Steven subsp. arctica (R. Brown) Pennell ex Hultén; Saarela et al. 2020); petal length ≤ 13 mm and anther length ≤ 1.5 mm (in contrast to all other Pedicularis species; Aiken et al. 2007). Hybrid individuals of P. hirsuta × P. langsdorffii subsp. arctica are reported from Lake Hazen, though they may resemble P. hirsuta in appearance, they can be distinguished by their variously extended styles (Sokoloff et al. 2015). Papaveraceae – Poppy family	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A278FFA1FF2D68143A035A3C.taxon	description	Figure 9 A, B	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A278FFA1FF2D68143A035A3C.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 25 ′ 52 ″ N, 062 ° 07 ′ 49 ″ W; 296 m a. s. l.; 16 Jul. 2019; habitat: wetland in a mountain pass, with peat and rocks as substrates, dominated by moss and Saxifraga cernua; QFA 0634992. Identification. Plants 2 – 13 cm high; herbaceous; caespitose. Taproots present. Stems 1 – 11 cm long; erect or ascending; hairy, with brown hairs. Leaves basal; alternate; petiolate. Petioles 5 – 30 mm long; flat; hairy, with pale brown hairs. Basal leaf blades 5 – 17 mm long, 2 – 10 mm wide; pinnatifid, with 1 terminal lobe and 2 or 3 main, ovate or oblong, acute lobes on each side (sometimes with secondary lobes); abaxial and adaxial surfaces both hairy, with dense white, yellow, or pale brown hairs; margins ciliate. Buds 10 – 12 mm long, 6 – 8 mm wide; less than twice as long as wide; ovoid; hairy, with dense dark brown hairs. Inflorescence a solitary flower. Sepals 2; 8 – 10 mm long, 4 – 6 mm wide; ovate; green or pinkish-brown; surface hairy, with dense dark brown hairs. Petals 4; 9 – 21 mm long, 12 – 22 mm wide; overlapping; obovate; unlobed; yellow or pale yellow (greenish-blue when withered); margins sometimes fringed. Androecium with 28 – 35 stamens and 0.9 – 1.0 mm long anthers. Gynoecium with 6 stigmatic rays. Fruit a capsule; 10 mm long, 7 mm wide; obpyriform (with its broadest part apically); slightly constricted just beneath the flat stigmatic disc; green; hairy, with dark brown hairs. Papaver dahlianum can be differentiated from some Canadian Arctic Papaver Linnaeus species by the pinnatifid blades, in contrast to pinnatisect blades found in P. labradoricum (Fedde) Solstad & Elven, P. lapponi- cum (Tolmatchew) Nordhagen, and P. hultenii Knaben (Solstad and Elven, unpublished). P. dahlianum and P. cornwallisense D. Löve are very similar but differ in the following characters: P. dahlianum has more stamens (30 – 50 stamens) than P. cornwallisense (≤ 24 stamens); P. dahlianum has longer buds (10 – 14 mm long) than P. cornwallisense (≤ 10 mm long); and P. dahlianum has nearly flat stigmatic discs, whereas they are convex in P. cornwallisense (Solstad and Elven unpublished). Poaceae – Grass family	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A279FFA0FCAF6C1E3DDD59D1.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 29 ′ 14 ″ N, 062 ° 02 ′ 05 ″ W; 20 m a. s. l.; 30 Jul. 2019; habitat: wetland near the ocean shore, with tussocks made of peat, dominated by Eriophorum triste and Alopecurus magellanicus; QFA 0635519 • same locality; 82 ° 27 ′ 49 ″ N, 062 ° 34 ′ 42 ″ W; 126 m a. s. l.; 25 Jul. 2019; habitat: wetland, with tussocks made of peat and till, dominated by Eriophorum triste, Arctagrostis latifo- lia, and Alopecurus magellanicus; QFA 0635547. Identification. Plants 14 – 27 cm high; herbaceous; not caespitose. Fibrous roots and rhizomes present. Stems 10 – 21 cm long; erect; glabrous. Leaves basal and cauline; alternate. Sheath margins scaberulous. Ligules 1.3 – 2.1 mm long. Basal leaf blades 16 – 58 mm long, 1.6 – 6.0 mm wide; linear; flat or involute; abaxial and adaxial sur- faces both scabrous; margins scabrous. Flag leaf blades 9 – 12 mm long, 0.8 – 1.5 mm wide. Inflorescence a dense or diffuse panicle; 30 – 75 mm long. Branches at lowest inflorescence node 4 – 5; 2.1 – 18.0 mm long. Pedicels sca- brous. Spikelets 4.0 – 4.8 mm long, 1.1 – 1.3 mm wide. Florets per spikelet 1 – 2. First glumes 2.4 – 2.9 mm long; lanceolate; surface glabrous; margins glabrous; apices acute. Second glumes 2.9 – 3.7 mm long (shorter than the lowest floret); lanceolate; vein 1; surface glabrous; mar- gins glabrous; apices acute. Lemmas 4.1 – 4.7 mm long, 0.7 – 0.9 mm wide; lanceolate; keeled; veins 3 – 5; surface dull and scabrous; apices acute and glabrous; awnless. Palea 3.9 – 4.1 mm long; veins scabrous. Rachilla between first and second lemmas 0.4 – 1.0 mm long. Androecium with 3 stamens and 2.0 – 2.4 mm long anthers. Gynoecium with 2 styles.	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A279FFA2FCAF689A3F975FA8.taxon	description	Figure 11 A	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A279FFA2FCAF689A3F975FA8.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 26 ′ 40 ″ N, 062 ° 43 ′ 09 ″ W; 210 m a. s. l.; 14 Jul. 2019; habitat: mesic, with peat and till as substrates, dominated by Juncus biglumis, moss, and blue-green algae (macroscopic sheet colonies dominated by Nostoc sp.); QFA 0635545 • same locality; 82 ° 29 ′ 58 ″ N, 062 ° 33 ′ 46 ″ W; 65 m a. s. l.; 6 Jul. 2019; habitat: mesic, with polygonal patterned ground made of till, dominated by Alopecurus magellanicus and moss; QFA 0635546. Identification. Plants 4 – 10 cm high; herbaceous; caespitose. Fibrous roots present. Stems 2 – 8 cm long; erect; glabrous. Leaves basal and cauline. Sheath margins glabrous. Ligules 2.6 – 3.7 mm long. Basal leaf blades 15 – 45 mm long, 0.4 – 1.1 mm wide; linear; rolled in bud or folded; abaxial surface glabrous; adaxial surface scabrous and hairy, with few short hairs apically; margins scabrous. Flag leaf blades 11.0 – 13.3 mm long, 0.5 – 0.6 (1.0 – 1.1 flat) mm wide. Inflorescence a dense pan- icle; 17 – 22 mm long. Branches at lowest inflorescence node 3 – 4; 1.8 – 6.2 mm long. Pedicels glabrous. Spikelets 3.6 – 4.9 mm long, 0.6 – 1.8 mm wide. Florets per spikelet 1 – 2. First glumes 2.7 – 3.1 mm long; lanceolate; surface glabrous; margins glabrous; apices acuminate or acute. Second glumes 2.8 – 3.4 mm long (almost as long as the lowest floret); lanceolate; veins 1 – 3; surface gla- brous; margins glabrous; apices acute. Lemmas 2.7 – 3.1 mm long, 0.5 – 0.7 mm wide; lanceolate; keeled; veins 5; surface shiny, glabrous, and hairy, with long hairs only at the base; apices acute or erose, and glabrous; awned. Awns 1.0 – 1.4 mm long; arising from the middle or below. Palea 1.8 – 2.6 mm long; veins scabrous. Rachilla between first and second lemmas 0.9 – 2.1 mm long. An- droecium with 3 stamens and 0.9 – 1.4 mm long anthers. Gynoecium with 2 styles. Deschampsia brevifolia and D. sukatschewii (Poplavskaja) Roshevitz are the two Deschampsia Palisot de Beauvois species on Ellesmere Island (Aiken et al. 2007; GBIF 2020). They can be differentiated by the following: D. brevifolia has dense panicles with strongly imbricate spikelets, whereas D. sukatschewii usually has open panicles with no or only moderately imbricate spikelets (Barkworth 2007; Saarela et al. 2020); the glumes and lemmas of D. brevifolia are usually dark purple proximally for over> ½ of their surface, whereas they usually are dark purple proximally over <½ of their surface in D. sukatschewii (Barkworth 2007; Saarela et al. 2020); D. brevifolia has keeled lemmas, whereas D. sukatschewii has rounded on the back lemmas (Aiken et al. 2007); and D. brevifolia has scabrous palea veins, whereas D. sukatschewii has glabrous palea veins (Aiken et al. 2007).	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A27BFFADFF2D6EA33C2A5459.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 30 ′ 04 ″ N, 062 ° 52 ′ 41 ″ W; 91 m a. s. l.; 2 Aug. 2019; habitat: xeric in a slope, with hummocks made of till and rocks, and sparse dominance of Saxifraga oppositifolia and moss; QFA 0635544. Identification. Plants 6.5 – 11.0 cm high; herbaceous; caespitose. Fibrous roots present. Stems 5 – 9 cm long; erect or ascending; hairy, with short hyaline hairs (densely hairy below the inflorescence). Leaves basal and cauline. Sheath margins glabrous. Ligules 0.1 – 0.2 mm long. Basal leaf blades 21 – 35 mm long, 0.3 – 0.4 mm wide; linear; rolled in bud or folded; abaxial surface glabrous; adaxial surface glabrous or hairy, with few short hairs; margins scabrous. Flag leaf blades 10.1 – 11.0 mm long, 0.3 – 0.5 mm wide; tip linear. Inflo- rescence a dense panicle; 14 – 25 mm long. Branches at lowest inflorescence node 1 – 2; 1.9 – 5.2 mm long. Pedi- cels scabrous. Spikelets 4.2 – 6.5 mm long, 1.9 – 3.1 mm wide. Florets per spikelet 2 – 3. First glumes 2.1 – 3.5 mm long; lanceolate; surface glabrous; margins ciliate; apices acuminate. Second glumes 3.3 – 4.0 mm long (shorter than the lowest floret); lanceolate; veins 3; surface gla- brous; margins ciliate; apices acuminate. Lemmas 3.2 – 4.3 mm long, 0.6 – 0.9 mm wide; lanceolate; rounded on the back; veins 4 – 5; surface dull and sparsely scabrous; apices ciliate; awned. Awn 1.4 – 1.6 mm long; arising from the tip. Palea 4.4 – 4.8 mm long; veins scabrous. Rachilla between first and second lemmas 0.4 – 1.1 mm long. Androecium with 3 stamens and 0.6 – 1.0 mm long. Gynoecium with 2 styles. The five Festuca Linnaeus species present on Elles- mere Island (GBIF 2020) were found in our survey. Among the four Festuca species without pseudoviviparous spikelets (F. baffinensis, F. brachyphylla Schultes & Schultes f. subsp. brachyphylla, F. edlundiae S. G. Aiken, Consaul, & Lefkovitch, and F. hyperborea Holmen ex Frederiksen; Aiken et al. 2007), F. baffinensis can be differentiated by having dense, short hairs on the culms, especially below the inflorescence, whereas F. brachyphylla, F. edlundiae, and F. hyperborea have glabrous or sparsely hairy culms (Aiken et al. 1995; Aiken et al. 2007). Festuca brachyphylla Schultes & Schultes f. subsp. brachyphylla Figures 10 C, 12 A Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 26 ′ 38 ″ N, 062 ° 11 ′ 23 ″ W; 178 m a. s. l.; 23 Jul. 2019; habitat: mesic, with polygonal patterned ground made of till, dominated by Alopecurus magellanicus; QFA 0635541. Identification. Plants 3.5 – 8.5 cm high; herbaceous; caespitose. Fibrous roots present. Stems 2.5 – 8.0 cm long; erect, ascending, or semi-prostrate; glabrous. Leaves basal and cauline. Sheath margins glabrous. Ligules 0.2 – 0.4 mm long. Basal leaf blades 14 – 22 mm long, 0.4 – 1.1 mm wide; linear; rolled in bud; abaxial surface glabrous; adaxial surface glabrous or scaberulous; margins scabrous. Flag leaf blades 2.8 – 7.0 mm long, 0.2 – 0.4 mm wide; tip linear. Inflorescence a dense panicle; 10 – 18 mm long. Branch at lowest inflorescence node 1; 1.9 – 2.1 mm long. Pedicels scabrous. Spikelets 5.9 – 6.2 mm long, 3.0 – 4.1 mm wide. Florets per spikelet 2 – 4. First glumes 1.8 – 2.3 mm long; lanceolate; surface glabrous; margins ciliate; apices acuminate. Second glumes 2.7 – 3.4 mm long (shorter than the lowest floret); lanceolate; veins 3; surface glabrous; margins ciliate; apices acute. Lemmas 3.3 – 4.1 mm long, 0.6 – 0.8 mm wide; lanceolate; rounded on the back; veins 5; surface dull and sparsely scabrous; apices glabrous or ciliate; awned. Awn 0.7 – 1.2 mm long; arising from the tip. Palea 3.6 – 3.9 mm long; veins scabrous. Rachilla between first and second lemmas 0.6 – 1.1 mm long. Androecium with 3 stamens and 1.0 – 1.3 mm long anthers. Gynoecium with 2 styles. Festuca brachyphylla subsp. brachyphylla, F. edlundiae, and F. hyperborea are very similar and can be differentiated by the following characters: short flag leaf blade with a spoon-shaped tip in F. hyperborea (0 – 8 mm long but usually <5 mm), whereas the flag leaf blade is longer with a linear tip in F. brachyphylla and F. edlundiae (2 – 15 mm long); culms of F. edlundiae are often semi-prostate (erect only at anthesis), whereas culms of the other species are erect; leaf cross section in F. edlundiae shows five well-developed ribs, whereas F. brachyphylla has one well-defined rib and 2 – 4 variously defined ribs, and F. hyperborea has five but less defined ribs than F. edlundiae (Fig. 12; Aiken et al. 1995). Moreover, shorter plants of F. brachyphylla are superficially simi- lar to F. hyperborea but are separated by the shape of the second glumes, which are supposed to be lanceolate in F. brachyphylla and obovate in F. hyperborea (Aiken et al. 1995; Aiken et al. 2007). However, we did not observe obovate second glumes in F. hyperborea; instead, they were more lanceolate or oblong.	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A274FFACFCAF6A1B3FFB58AA.taxon	description	Figures 11 B, 12 B	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A274FFACFCAF6A1B3FFB58AA.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 26 ′ 58 ″ N, 062 ° 33 ′ 50 ″ W; 198 m a. s. l.; 17 Jul. 2019; habitat: mesic, with polygonal patterned ground made of till and rocks, dominated by Phippsia algida (Solander) R. Brown, Juncus biglumis, and moss; QFA 0635542 • same locality; 82 ° 26 ′ 42 ″ N, 062 ° 12 ′ 12 ″ W; 184 m a. s. l.; 23 Jul. 2019; habitat: xeric, with polygonal patterned ground made of till and rocks, and sparse dominance of Saxifraga oppositifolia; QFA 0635543. Identification. Plants 5.5 – 7.5 cm high; herbaceous; caespitose. Fibrous roots present. Stems 4.5 – 7.0 cm long; prostrate, semi-prostrate, or ascending; glabrous. Leaves basal and cauline. Sheath margins glabrous. Ligules 0.4 – 0.5 mm long. Basal leaf blades 20 – 26 mm long, 0.4 – 0.7 mm wide; linear; rolled in bud; abaxial surface glabrous or scabrous; adaxial surface glabrous; margins scabrous or glabrous. Flag leaf blades 5 – 14 mm long, 0.3 – 0.4 mm wide; tip linear. Inflorescence a dense panicle; 11 – 20 mm long. Branches at lowest inflorescence node 1 – 2; 1.1 – 3.2 mm long. Pedicels scabrous. Spikelets 6.0 – 7.9 mm long, 3.3 – 3.8 mm wide. Florets per spikelet 2 – 4. First glumes 1.8 – 2.2 mm long; lanceolate; surface glabrous; margins glabrous; apices acuminate. Second glumes 2.4 – 4.3 mm long (shorter than the lowest floret); ovate; veins 1 – 3; surface glabrous; margins ciliate; apices acute. Lemmas 3.2 – 4.1 mm long, 0.7 – 0.9 mm wide; lanceolate; rounded on the back; veins 5; surface dull and sparsely scabrous; apices ciliate; awned. Awn 0.9 – 1.3 mm long; arising from the tip. Palea 3.6 – 3.8 mm long; veins scabrous. Rachilla between first and second lemmas 0.9 – 1.0 mm long. An- droecium with 3 stamens and 1.0 – 1.9 mm long anthers. Gynoecium with 2 styles. Characteristics allowing to distinguish F. edlundiae from the other Festuca species present on Ellesmere Island can be found under F. baffinensis and F. brachyphylla subsp. brachyphylla.	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A275FFACFF2D69A03A795BF6.taxon	description	Figures 11 C, D, 12 C	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A275FFACFF2D69A03A795BF6.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 27 ′ 41 ″ N, 062 ° 01 ′ 06 ″ W; 121 m a. s. l.; 6 Aug. 2019; habitat: mesic habitat, with till and rocks as substrates, dominated by Saxifraga oppositifo- lia and moss; QFA 0635522. Identification. Plants 4.5 – 9.0 cm high; herbaceous; caespitose. Fibrous roots present. Stems 3.5 – 7.0 cm long; erect or ascending; glabrous. Leaves basal and cauline. Sheath margins glabrous. Ligules 0.3 – 0.5 mm long. Basal leaf blades 3.5 – 28.0 mm long, 0.2 – 0.6 mm wide; linear; rolled in bud; abaxial and adaxial surfaces both glabrous; margins scabrous. Flag leaf blades 0.5 – 3.7 mm long, 0.2 – 0.4 mm wide; tip spoon – shaped. Inflorescence a dense panicle; 12 – 18 mm long. Branch at lowest inflorescence node 1; 0.9 – 2.3 mm long. Pedicels scabrous. Spikelets 6.4 – 6.8 mm long, 2.5 – 2.9 mm wide. Florets per spikelet 2 – 4. First glumes 1.8 – 2.7 mm long; lanceolate; surface glabrous; margins ciliate; apices acuminate. Second glumes 2 – 3 mm long (shorter than the lowest floret); lanceolate or oblong; veins 3; surface glabrous; margins ciliate; apices acute. Lemmas 3.4 – 3.9 mm long, 0.8 – 0.9 mm wide; lanceolate; rounded on the back; veins 5; surface dull and sparsely scabrous; apices ciliate; awned. Awn 1.3 – 1.7 mm long; arising from the tip or slightly below. Palea 3.3 – 3.6 mm long; veins scabrous. Rachilla between first and second lemmas 0.7 – 1.0 mm long. An- droecium with 3 stamens and 0.5 – 1.5 mm long anthers. Gynoecium with 2 styles. Characteristics allowing to distinguish F. hyperborea from the other Festuca species present on Ellesmere Island can be found under F. baffinensis and F. brachyphylla subsp. brachyphylla.	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A275FFAFFCAF6AF43C9C5A59.taxon	description	Figures 11 E, 12 D	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A275FFAFFCAF6AF43C9C5A59.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 30 ′ 04 ″ N, 062 ° 52 ′ 41 ″ W; 93 m a. s. l.; 2 Aug. 2019; habitat: xeric in a slope, with hummocks made of till and rocks, dominated by Saxifraga oppositi- folia and moss; QFA 0635517 • same locality; 82 ° 29 ′ 12 ″ N, 062 ° 50 ′ 55 ″ W; 86 m a. s. l.; 27 Aug. 2019; habitat: mesic in a slope, with peat and till as substrates, dominated by Salix arctica, Saxifraga oppositifolia, Stellaria longipes, and Puccinellia vahliana (Liebmann) Scribner & Merrill; QFA 0635540 • same locality; 82 ° 30 ′ 21 ″ N, 062 ° 41 ′ 20 ″ W; 66 m a. s. l.; 1 Aug. 2019; habitat: mesic in a slope, with till and rocks as substrates, dominated by Salix arctica; QFA 0635587. Identification. Plants 7.0 – 15.5 cm high; herbaceous; caespitose. Fibrous roots present. Stems 6 – 14 cm long; erect; glabrous and scabrous on angles below the inflo- rescence. Leaves basal and cauline. Sheath margins glabrous or hairy, with short simple hairs. Ligules 0.2 – 0.5 mm long. Basal leaf blades 12 – 25 mm long, 0.3 – 0.7 mm wide; linear; folded or rolled in bud; abaxial surface glabrous or scabrous; adaxial surface scabrous; margins glabrous or scabrous. Flag leaf blades 10.9 – 11.2 mm long, 0.2 – 0.3 mm wide; tip linear. Inflorescence a dense pani- cle, with bulbils allowing vegetative reproduction; 26 – 30 mm long. Branch at lowest inflorescence node 1; 1.5 – 2.2 mm long. Pedicels scabrous. Spikelets 10 – 14 mm long, 1.1 – 2.0 mm wide. Florets per spikelet 2 or 3. First glumes 2.8 – 3.1 mm long; lanceolate; surface glabrous or hairy, with hairs at the apices only; margins ciliate; apices acuminate. Second glumes 3.9 – 4.0 mm long (shorter than the lowest lemma); lanceolate; veins 3; surface glabrous and scabrous apically; margins ciliate; apices acute. Lemmas 4.1 – 6.7 mm long, 0.6 – 0.8 mm wide; lanceolate; keeled; veins 5; surface dull, sparsely scabrous, and hairy apically (on the projection), with short hairs; apices acuminate and glabrous; awnless. Palea vestigial or absent. Rachilla absent. Bulbils 3.3 – 9.6 mm long. Androecium and gynoecium absent. Among the five Festuca species present on Ellesmere Island (GBIF 2020), F. viviparoidea subsp. viviparoidea is the only one with pseudoviviparous spikelets (in contrast to F. baffinensis, F. brachyphylla subsp. brachyphylla, F. edlundiae, and F. hyperborea; Aiken et al. 2007).	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A276FFAFFF2D6B123DD05BD5.taxon	description	Figure 11 F	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A276FFAFFF2D6B123DD05BD5.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 26 ′ 40 ″ N, 062 ° 43 ′ 09 ″ W; 210 m a. s. l.; 14 Jul. 2019; habitat: mesic, with peat and rocks as substrates, dominated by Juncus biglumis, moss, and blue-green algae (macroscopic sheet colonies dominated by Nostoc sp.); QFA 0635538 • same locality; 82 ° 25 ′ 52 ″ N, 062 ° 07 ′ 49 ″ W; 296 m a. s. l.; 16 Jul. 2019; habitat: wetland in a mountain pass, with peat and rocks as substrates, dominated by moss and Saxifraga cernua; QFA 0635539. Identification. Plants 3.5 – 6.0 cm high; herbaceous; caespitose. Fibrous roots present. Stems 2.5 – 4.0 cm long; erect, ascending, or decumbent; glabrous. Leaves basal and cauline. Sheath margins glabrous. Ligules 0.8 – 1.0 mm long. Basal leaf blades 8 – 20 mm long, 0.8 – 1.2 (1.5 – 2.8 flat) mm wide; linear; folded or flat; abaxial and adaxial surfaces both glabrous; margins glabrous. Flag leaf blades 6 – 13 mm long, 0.7 – 1.2 (1.7 – 2.1 flat) mm wide. Inflorescence a dense panicle; 9 – 20 mm long. Branches at lowest inflorescence node 4 – 6; 1.0 – 2.8 mm long. Pedicels glabrous. Spikelets 1.6 – 2.3 mm long, 0.8 – 1.1 mm wide. Floret per spikelet 1. First glumes 0.3 – 0.5 mm long; ovate; surface glabrous; margins glabrous; apices obtuse. Second glumes 0.4 – 0.7 mm long (shorter than the lowest floret); ovate; veins indistinct; surface glabrous; margins glabrous; apices obtuse. Lemmas 1.4 – 2.0 mm long, 0.7 – 1.1 mm wide; ovate; rounded on the back; veins 1 – 3; surface dull, glabrous, and hairy, with hairs on and between the veins proximally (hairs 0.07 – 0.17 mm long; covering the lower ½ of the lemma surface); apices acute or erose, and glabrous; awnless. Palea 1.3 – 1.9 mm long; veins hairy. Androecium with 1 or 2 stamens and 0.4 – 0.6 mm long anthers. Gynoecium with 2 styles. Fruit a caryopsis; 1.4 – 1.5 mm long, 0.3 – 0.5 mm wide; ellipsoid. Most authors recognize two Phippsia (Trinius) R. Brown species, P. algida and P. concinna (Th. Fries) Lindeberg (Steen et al. 2004; Aiken et al. 2007; Consaul and Aiken 2007), although Soreng and contributors (2003) treated the latter taxon as Phippsia algida subsp. concinna (Th. Fr.) Á. Löve & D. Löve; both taxa are known from Ellesmere Island. The most reliable characters to differentiate the species are the number of stamens (1 or 2 stamens in P. algida and 1 stamen in P. concinna); caryopsis shape (ellipsoid in P. algida and ovoid in P. concinna); pedicel angle (5 – 8 ° in P. algida and 20 – 108 ° in P. concinna); lemma hairiness (hairs on lower 1 / 3 or entirely glabrous in P. algida and hairs on the 1 / 2 – 2 / 3 in P. concinna); and lemma hair length (0.02 – 0.15 mm long in P. algida, and 0.19 – 0.24 mm long in P. concinna; Aares et al. 2000). In addition, P. algida has spikelets that are less than twice as long as wide, whereas P. concinna has spikelets 2 – 3 times longer than wide (Consaul and Aiken 2007). We found that the lemmas of the P. algida specimens from Alert had longer hairs (up to 0.17 mm long) on a larger surface (½ of the surface) than reported in the literature. Phippsia algida can also be mistaken for the hybrid × Pucciphippsia vacillans, which is also known from Alert and is somewhat intermediate between Phippsia algida and Puccinellia vahliana (Hedberg 1962; Steen et al. 2004). They both have very short glumes (≤ 0.8 mm long; Aiken et al. 2007), but × P. vacillans differs from P. algida by having longer leaf blades (≥ 30 mm long), more than one floret per spikelet, and panicles with predom- inantly ascending branches, not erect as in P. algida (Aiken et al. 2007).	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A276FFAEFCAF6A973F955801.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 26 ′ 26 ″ N, 062 ° 01 ′ 49 ″ W; 147 m a. s. l.; 23 Jul. 2019; habitat: wetland on the margins of a lake, with peat as substrate, dominated by moss and Luzula nivalis; QFA 0635537. Identification. Plants 9.5 – 19.5 cm high; herbaceous; not caespitose. Fibrous roots and rhizomes present. Stems 5 – 14 cm long; erect or ascending; glabrous. Leaves basal and cauline. Sheath margins glabrous. Ligules 1.8 – 2.6 mm long. Basal and cauline leaf blades (attached below the middle of the stem) 24.5 – 59.0 mm long, 0.9 – 1.1 (2.0 – 2.6 flat) mm wide; linear; folded or flat; abaxial and ad- axial surfaces both glabrous; margins glabrous. Flag leaf blades absent or present; 8.8 – 16.0 mm long, 0.9 – 1.3 mm wide. Inflorescence a diffuse raceme with spikelets at- tached on one side; 43 – 60 mm long. Branches at lowest inflorescence node 1; 1 – 12 mm long. Pedicels glabrous. Spikelets 4.8 – 12.5 mm long, 1.6 – 3.5 mm wide. Florets per spikelet 6 – 10. First glumes 1.5 – 2.1 mm long; ovate; surface glabrous; margins glabrous; apices obtuse. Second glumes 1.8 – 2.8 mm long (shorter than the lowest flo- ret); ovate; veins 3; surface glabrous; margins glabrous; apices rounded. Lemmas 3.6 – 4.0 mm long, 1.1 – 1.2 mm wide; oblanceolate; rounded on the back; veins 5 – 7; surface dull and hairy, with short hairs on and between the veins; apices rounded and glabrous; awnless. Palea 3.6 – 4.2 mm long; veins scabrous; with awn arising near the base of each palea keel; awns 2.6 – 3.5 mm long. Rachilla between first and second lemmas 0.9 – 1.3 mm long. An- droecium with 3 stamens and 2.2 – 2.9 mm long anthers. Gynoecium with 2 styles.	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A277FFAEFF2D69CA3D815FA8.taxon	description	Figures 10 D, E, 11 G	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A277FFAEFF2D69CA3D815FA8.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 29 ′ 43 ″ N, 61 ° 57 ′ 15 ″ W; 14 m a. s. l.; 30 Jul. 2019; habitat: xeric in a slope, with till and rocks as substrates, and sparse dominance of Salix arctica; QFA 0635535 • same locality; 82 ° 28 ′ 11 ″ N, 062 ° 05 ′ 06 ″ W; 118 m a. s. l.; 18 Jul. 2019; habitat: mesic, with polygonal patterned ground made of till and rocks, dominated by Stellaria longipes; QFA 0635536. Identification. Plants 5.0 – 9.5 cm high; herbaceous; caespitose. Fibrous roots present. Stems 4 – 8 cm long; erect or ascending; glabrous. Leaves basal and cauline. Sheath margins glabrous. Ligules 0.7 – 1.0 mm long. Basal leaf blades 12 – 41 mm long, 0.2 – 0.8 mm wide; linear; folded or rolled in bud; abaxial and adaxial surfaces both glabrous; margins scabrous or glabrous. Flag leaf blades 3.7 – 11.0 mm long, 0.3 – 0.8 mm wide. Inflorescence a dense panicle; 10 – 21 mm long. Branches at lowest inflo- rescence node 1 – 2; 2.1 – 3.5 mm long. Pedicels glabrous. Spikelets 4.7 – 5.4 mm long, 1.8 – 2.4 mm wide. Florets per spikelet 2 – 4. First glumes 3.0 – 3.4 mm long; lanceolate; surface glabrous; margins glabrous; apices acuminate or acute. Second glumes 3.3 – 4.1 mm long (almost as long as the lowest floret); lanceolate or ovate; veins 1 – 3; surface glabrous; margins glabrous; apices acuminate or acute. Lemmas 3.3 – 3.8 mm long, 0.8 – 1.1 mm wide; lanceolate; keeled; veins 5; surface dull and hairy proximally on the 3 / 4 of the surface, with hairs on and between the veins; apices obtuse or erose, and glabrous; awnless. Palea 2.7 – 3.3 mm long; veins scabrous. Rachilla between first and second lemmas 0.5 – 1.1 mm long. Androecium with 3 stamens and 0.7 – 1.2 mm long anthers. Gynoecium with 2 styles. There are five Poa Linnaeus species on Ellesmere Island (P. abbreviata subsp. abbreviata, P. arctica R. Brown subsp. arctica and subsp. caespitans Simmons ex Nannfeldt, P. glauca Vahl subsp. glauca, P. hartzii Gandoger subsp. hartzii, and P. pratensis Linnaeus subsp. alpigena (Lindman) Hiitonen and subsp. colpodea (Th. Fries) Tzvelev; GBIF 2020). Among them, only P. arctica subsp. arctica and the two P. pratensis subspecies have rhizomes (Saarela et al. 2020). P. abbreviata subsp. abbreviata differs from the remaining caespitose species lacking rhizomes (P. arctica subsp. caespitans, P. glauca subsp. glauca, P. hartzii subsp. hartzii) by having in general a shorter inflorescence (≤ 2.2 cm long) in contrast to inflorescences reaching up to 6 cm long in the other spe- cies (Aiken et al. 2007) and by having well developed and shorter anthers (0.1 – 1.2 mm long) in contrast to well developed or aborted, 1.0 – 2.5 mm long anthers (Saarela et al. 2020).	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A277FFA9FCAF6EA33F265EB2.taxon	description	Figures 11 H	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A277FFA9FCAF6EA33F265EB2.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 26 ′ 26 ″ N, 062 ° 01 ′ 49 ″ W; 147 m a. s. l.; 23 Jul. 2019; habitat: wetland on the margins of a lake, with peat as substrate, dominated by moss and Luzula nivalis; QFA 0635534. Identification. Plants 5.3 – 12.5 cm high; herbaceous; not caespitose. Fibrous roots and rhizomes present. Stems 2.5 – 10.0 cm long; erect or ascending; glabrous. Leaves basal and cauline. Sheath margins glabrous. Ligules 1.3 – 1.7 mm long. Basal leaf blades 21 – 26 mm long, 0.6 – 0.8 (1.5 – 1.8 flat) mm wide; linear; rolled or folded in bud; abaxial surface glabrous and scabrous apically; adaxial surface glabrous; margins scabrous. Flag leaf blades 12.5 – 13.9 mm long, 0.7 – 0.9 mm wide. Inflorescence a dif- fuse panicle; 21.0 – 31.5 mm long. Branches at lowest inflorescence node 1 – 3; 10 – 22 mm long. Pedicels scabrous. Spikelets 3.7 – 5.1 mm long, 0.9 – 2.3 mm wide. Florets per spikelet 1 – 4. First glumes 2.6 – 3.2 mm long; lanceolate; surface glabrous; margins glabrous; apices acuminate. Second glumes 3.1 – 3.5 mm long (shorter than, or almost as long as, the lowest floret); lanceolate or ovate; veins 3; surface glabrous and scabrous on midvein; margins glabrous; apices acute. Lemmas 3.1 – 3.5 mm, long 1.0 – 1.2 mm wide; ovate or lanceolate; keeled; veins 5; surface dull, glabrous, and hairy, with hairs on and between the veins proximally; apices acute or erose, and glabrous; awnless. Palea 2.4 – 3.5 mm long; veins hairy, with short (proximally) and long hairs (in the middle) (hairs also present between the veins). Rachilla between first and second lemmas 1.1 – 2.0 mm long. Androecium with 3 stamens and 1.3 – 1.5 mm long anthers. Gynoecium with 2 styles. Two Poa species present on Ellesmere Island have rhizomes (P. arctica subsp. arctica and P. pratensis subsp. arctica and subsp. caespitans; GBIF 2020). They can be differentiated based on the following: P. pratensis subsp. colpodea has at least some bulbiferous spikelets (in contrast to the others that do not have bulbils at all; Aiken et al. 2007); P. arctica subsp. arctica has open, pyramidal inflorescences, whereas both P. pratensis subspecies have usually contracted, lanceolate or narrowly pyramidal inflorescences (Aiken et al. 2007; Saarela et al. 2020); and P. arctica subsp. arctica has paleas softly puberulent between keels, whereas both P. pratensis subspecies have paleas glabrous between keels (Saarela et al. 2020).	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A270FFA9FF2D6FB83C815458.taxon	description	Figures 11 I	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A270FFA9FF2D6FB83C815458.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 28 ′ N, 062 ° 06 ′ W; 117 m a. s. l.; 18 Aug. 2019; habitat: around an Arctic fox den; QFA 0635518 • same locality; 82 ° 28 ′ 16 ″ N, 062 ° 06 ′ 24 ″ W; 122 m a. s. l.; 18 Jul. 2019; habitat: around a bird perching site; QFA 0635533. Identification. Plants 7.5 – 16.5 cm high; herbaceous; not caespitose. Fibrous roots and rhizomes present. Stems 5.5 – 14.0 cm long; erect; glabrous. Leaves basal and cauline. Sheath margins glabrous. Ligules 0.8 – 1.3 mm long. Basal leaf blades 17 – 46 mm long, 0.8 – 1.1 mm wide; linear; folded or rolled in bud; abaxial and adaxial surfaces both glabrous; margins glabrous. Flag leaf blades 8.5 – 9.5 mm long, 0.3 – 0.6 mm wide. Inflorescence a diffuse or dense panicle, with bulbils allowing vegetative reproduction; 22.0 – 33.5 mm long. Branches at lowest inflores- cence node 2 or 3; 0.9 – 2.8 mm long. Pedicels glabrous. Spikelets 4 – 9 mm long, 1.5 – 2.3 mm wide. Florets per spikelet 1 – 3. First glumes 2.3 – 3.0 mm long; ovate; surface glabrous; margins glabrous; apices acute or acuminate. Second glumes 2.0 – 2.9 mm long (shorter than, or almost as long as, the lowest lemma); ovate or lanceolate; veins 3; surface glabrous and scabrous on the midvein (midvein sometimes glabrous); margins glabrous; apices acute or acuminate. Lemmas 2.1 – 3.7 mm long, 0.6 – 1.7 mm wide; lanceolate; keeled; veins 5; surface dull, glabrous proximally, hairy on the veins, and scabrous apically; apices acute and glabrous; awnless. Palea present or absent; 1.6 – 1.8 mm long; veins scabrous (hairs absent between the veins). Rachilla between first and second lemmas 0.2 – 0.3 mm long. Bulbils 3.4 – 8.9 mm long. Androecium and gynoecium absent. Characteristics allowing to distinguish P. pratensis subsp. colpodea from the other Poa species present on Ellesmere Island can be found under P. abbreviata subsp. abbreviata and P. arctica subsp. arctica.	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A270FFA8FCAF6DC23C115EC4.taxon	description	Figures 10 F, 11 J	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A270FFA8FCAF6DC23C115EC4.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 31 ′ 04 ″ N, 062 ° 28 ′ 48 ″ W; 66 m a. s. l.; 27 Jul. 2019; habitat: mesic, with hummocks made of till, dominated by Stellaria longipes, Saxifraga oppositifo- lia, and moss; QFA 0635529 • same locality; 82 ° 29 ′ 56 ″ N, 062 ° 19 ′ 19 ″ W; 48 m a. s. l.; 8 Aug. 2019; habitat: xeric near the sewage outlet, with till and rocks as substrates, and sparse dominance of Puccinellia angustata and Cochle- aria groenlandica; QFA 0635530. Identification. Plants 10.5 – 24.0 cm high; herbaceous; caespitose. Fibrous roots present. Stems 8 – 21 cm long; erect, ascending, or prostrate; glabrous and sometimes scabrous below the inflorescence. Leaves basal and cau- line. Sheath margins glabrous or scabrous. Ligules 1.3 – 1.7 mm long. Basal leaf blades 25 – 84 mm long, 0.7 – 0.9 (1.4 – 1.5 flat) mm wide; linear; rolled in bud or flat; abax- ial and adaxial surfaces both glabrous; margins glabrous or scabrous. Flag leaf blades 26 – 48 mm long, 0.3 – 0.1 mm wide. Inflorescence a diffuse or dense panicle; 30 – 57 mm long. Branches at lowest inflorescence node 3; 2.9 – 11.5 mm long. Pedicels scabrous. Spikelets 4.1 – 6.7 mm long, 1.5 – 2.0 mm wide. Florets per spikelet 3 – 5. First glumes 1.0 – 1.6 mm long; lanceolate; surface glabrous; margins scabrous; apices acuminate. Second glumes 2.4 – 2.8 mm long (shorter than the lowest floret); lanceolate; veins 3; surface glabrous; margins scabrous; apices acuminate. Lemmas 3.0 – 3.9 mm long, 0.6 – 0.8 mm wide; lanceolate; rounded on the back and with straight lemma tips; veins 4 or 5; surface dull, glabrous, and hairy, with hairs on and between the veins proximally; apices acute or erose, and glabrous or scabrous; awnless. Palea 2.4 – 2.8 mm long; veins hairy proximally, with curly simple hairs, and scabrous apically. Rachilla between first and second lemmas 1.0 – 1.5 mm long. Androecium with 3 stamens and 0.8 – 1.2 mm long anthers. Gynoecium with 2 styles. There are seven Puccinellia Parlatore species present on Ellesmere Island (GBIF 2020). One of them, P. phryganodes subsp. neoarctica, is spreading by leafy stolons, whereas the others are caespitose and do not have stolons (Consaul and Gillespie 2001; Aiken et al. 2007). The remaining species can be separated using the following combination of characters: in P. angustata, P. bruggemannii, and P. vahliana the palea veins have curly, intertwined hairs proximally and are scabrous apically, in contrast to being glabrous proximally and scabrous or smooth distally in P. andersonii Swallen, P. arctica (Hooker) Fernald & Weatherby, and P. vaginata (Lange) Fernald & Weatherby (Aiken et al. 2007; Saarela et al. 2020). Among the three former species, P. vahliana has smooth pedicels, whereas they are scabrous in P. angustata and P. bruggemannii (Saarela et al. 2020). Inflores- cences, second glumes, and lemmas are reported to be longer in P. angustata (inflorescences 4 – 13 cm long; sec- ond glumes 1.9 – 3.0 mm long, with a length-width ratio of 0.3 – 0.6; lemmas 3.5 – 5.2 mm long) than in P. bruggemannii (inflorescences 1 – 4 cm long; second glumes 1.7 – 2.3 mm long, with a length-width ratio of 0.5 – 0.8; lemmas 2.8 – 3.8 mm long; Saarela et al. 2020). However, we found that using only the length of the inflorescences, glumes, and lemmas did not unambiguously differentiate the two species. Indeed, we had specimens of P. angustata with shorter inflorescences (e. g., 3 cm long) and lem- mas (e. g., 3 mm long), and specimens of P. bruggemannii with longer inflorescences (e. g., 4.5 cm long), glumes (e. g., 2.9 mm long), and lemmas (e. g., 4 mm long). We found however that the presence of incurved lemma tips in P. bruggemannii and straight lemma tips in P. angustata was a good identification criterion, as well as an anther length> 0.8 mm and a plant height> 10 cm (Consaul et al. 2008 a; Saarela et al. 2020).	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A271FFA8FF2D6F873D935FB5.taxon	description	Figure 11 K	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A271FFA8FF2D6F873D935FB5.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 27 ′ 28 ″ N, 062 ° 03 ′ 55 ″ W; 140 m a. s. l.; 26 Jul. 2019; habitat: xeric, with polygonal patterned ground made of till and rocks, and sparse dominance of Stellaria longipes and Saxifraga oppositifolia; QFA 0635526 • same locality; 82 ° 24 ′ 36 ″ N, 062 ° 43 ′ 04 ″ W; 369 m a. s. l.; 17 Jul. 2019; habitat: barren ground, with till and rocks as substrates; QFA 0635527 • same locality; 82 ° 28 ′ 01 ″ N, 062 ° 10 ′ 01 ″ W; 141 m a. s. l.; 18 Jul. 2019; hab- itat: xeric, with polygonal patterned ground made of till and rocks, and sparse dominance of Saxifraga oppositi- folia; QFA 0635528. Identification. Plants 4 – 10 cm high; herbaceous; caespitose. Fibrous roots present. Stems 2 – 8 cm long; erect, ascending, or semi-prostrate; glabrous. Leaves basal and cauline. Sheath margins glabrous or scabrous. Ligules 0.4 – 1.4 mm long. Basal leaf blades 8 – 30 mm long, 0.4 – 0.9 mm wide; linear; folded or rolled in bud; abaxial and adaxial surfaces both glabrous; margins glabrous. Flag leaf blades 2.8 – 20.0 mm long, 0.4 – 0.7 mm wide. Inflo- rescence a dense panicle; 12 – 45 mm long. Branches at lowest inflorescence node 2 – 3; 1.4 – 9.5 mm long. Pedi- cels scabrous. Spikelets 3.5 – 4.1 mm long, 1.6 – 2.5 mm wide. Florets per spikelet 2 – 4. First glumes 1.1 – 2.0 mm long; ovate; surface glabrous; margins glabrous or scabrous; apices acute. Second glumes 1.9 – 2.9 mm long (shorter than, or almost as long as, the lowest floret); lanceolate; veins 3; surface glabrous; margins glabrous or scabrous; apices obtuse. Lemmas 2.2 – 4.0 mm long, 0.5 – 0.9 mm wide; elliptic; rounded on the back and with incurved lemma tips; veins 5; surface dull (and shiny apically), glabrous, and hairy, with hairs on the veins proximally; apices acute or erose, and slightly scabrous; tip incurved; awnless. Palea 2.3 – 2.9 mm long; veins hairy proximally, with simple curly hairs, and scabrous apically. Rachilla between first and second lemmas 0.7 – 1.2 mm long. Androecium with 3 stamens and 0.6 – 0.8 mm long anthers. Gynoecium with 2 styles. Characteristics allowing to distinguish P. bruggemannii from the other Puccinellia species present on Ellesmere Island can be found under P. angustata. Puccinellia phryganodes (Trinius) Scribner & Merrill subsp. neoarctica (Á. Löve & D. Löve) Elven Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 31 ′ 31 ″ N, 062 ° 11 ′ 49 ″ W; 0 m a. s. l.; 3 Aug. 2019; habitat: ocean shore, with sand and rocks as substrates; QFA 0635525. Identification. Plants 2.0 – 3.5 cm high; herbaceous; caespitose. Fibrous roots and stolons (growing in a zigzag pattern) present. Stolons 2 – 8 cm long; prostrate; glabrous. Leaves basal and along the stolons. Sheath margins glabrous. Ligules 0.3 – 0.8 mm long. Basal leaf blades 10.0 – 19.8 mm long, 0.2 – 0.5 mm wide; linear; involute, rolled in bud, or folded; abaxial and adaxial surfaces both glabrous; margins glabrous. Cauline leaf blades (emerging from stolons) 4.0 – 9.8 mm long, 0.2 – 0.5 mm wide. Inflo- rescence not observed at Alert. Characteristics allowing to distinguish P. phryganodes subsp. neoarctica from the other Puccinellia species present on Ellesmere Island can be found under P. angustata.	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A271FFABFCAF6EB13C7E5E1E.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 26 ′ 38 ″ N, 062 ° 11 ′ 23 ″ W; 178 m a. s. l.; 23 Jul. 2019; habitat: mesic, with polygonal patterned ground made of till, dominated by Alopecurus magellanicus; QFA 0635523 • same locality; 82 ° 31 ′ 13 ″ N, 062 ° 14 ′ 26 ″ W; 10 m a. s. l.; 3 Aug. 2019; habitat: mesic in a slope, with till and rocks as substrates, dominated by Salix arctica; QFA 0635524 • same locality; 82 ° 27 ′ 33 ″ N, 61 ° 58 ′ 45 ″ W; 120 m a. s. l.; 6 Aug. 2019; habitat: mesic, with till and rocks as substrates, dominated by Alope- curus magellanicus and moss; QFA 0635531 • same locality; 82 ° 27 ′ 29 ″ N, 062 ° 08 ′ 34 ″ W; 155 m a. s. l.; 6 Aug. 2019; habitat: wetland, with peat, till, and rocks as substrates, dominated by Alopecurus magellanicus and moss; QFA 0635532. Identification. Plants 7.0 – 17.5 cm high; herbaceous; caespitose. Fibrous roots present. Stems 4.0 – 14.5 cm long; erect or ascending; glabrous. Leaves basal and cauline. Sheath margins glabrous. Ligules 1.8 – 2.7 mm long. Basal leaf blades 11 – 33 mm long, 0.4 – 0.7 (1.0 – 1.7 flat) mm wide; linear; rolled in bud or folded; abaxial and adaxial surfaces both glabrous; margins glabrous. Flag leaf blades 3.3 – 20.0 mm long, 0.25 – 0.80 (1.1 – 1.3 flat) mm wide. Inflorescence a dense panicle; 25 – 45 mm long. Branches at lowest inflorescence node 2 – 3; 1.0 – 6.3 mm long. Pedicels glabrous. Spikelets 3.5 – 5.8 mm long, 1.2 – 2.5 mm wide. Florets per spikelet 2 or 3. First glumes 1.5 – 2.9 mm long; lanceolate; surface glabrous; margins glabrous or scabrous; apices acute. Second glumes 2.1 – 3.6 mm long (shorter than, or almost as long as, the lowest floret); ovate; veins 1 – 3; surface glabrous; mar- gins glabrous or scabrous; apices acute. Lemmas 2.4 – 4.2 mm long, 0.5 – 0.9 mm wide; lanceolate; rounded on the back and with straight lemma tips; veins 3; surface dull, glabrous, and hairy, with hairs on and between the veins proximally; apices acute or erose, and glabrous; awnless. Palea 2.7 – 3.7 mm long; veins hairy proximally, with simple curly hairs, and scabrous apically. Rachilla between first and second lemmas 0.7 – 1.4 mm long. Androecium with 3 stamens and 0.8 – 1.8 mm long anthers. Gynoecium with 2 styles. Characteristics allowing to distinguish P. vahliana from the other Puccinellia species present on Ellesmere Island can be found under P. angustata.	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A272FFABFF2D6A973DFA5FDB.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 28 ′ 14 ″ N, 062 ° 24 ′ 04 ″ W; 112 m a. s. l.; 9 Aug. 2019; habitat: wetland, with peat and till as substrates, dominated by Eriophorum triste, Alopecurus magellanicus, moss, and blue-green algae (macroscopic sheet colonies dominated by Nostoc sp.); QFA 0635578. Identification. Plants 4.0 – 7.5 cm high; herbaceous; not caespitose. Fibrous roots and rhizomes present. Stems 2.5 – 5.0 cm long; erect; glabrous. Leaves basal and cauline; heterophyllous; alternate; petiolate. Petioles 1 – 20 mm long; glabrous; adnate, with ocrea. Basal leaf blades 11 – 34 mm long, 3 – 6 mm wide; lanceolate or elliptic; bases attenuate or cuneate; abaxial surface hairy, with hyaline non-glandular hairs; adaxial surface shiny and glabrous; margins slightly revolute and glabrous; apices acute. Cauline leaf blades 5 – 18 mm long, 1 – 3 mm wide. Inflorescences a spike, with sessile bulbils throughout or with sessile bulbils proximally and 1 – 4 pedicellate flow- ers apically; 14 – 28 mm long. Bulbils 1.5 – 2.7 mm long, 1.0 – 1.7 mm wide; pyriform; reddish-purple or dark purple; surface glabrous. Tepals 5; 1.5 – 2.1 mm long, 0.7 – 1.4 mm wide; petaloid; obovate; white or pink. Androecium with 5 – 8 stamens and 0.2 – 0.3 mm long anthers. Gynoecium with 3 styles and 1 stigma per style. Fruit not observed at Alert.	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A272FFABFCAF6E903A895AA6.taxon	description	Figure 13 A – C	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A272FFABFCAF6E903A895AA6.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 31 ′ 03 ″ N, 062 ° 26 ′ 20 ″ W; 58 m a. s. l.; 2 Jul. 2019; habitat: barren ground near a river, with till and rocks as substrates; QFA 0635579. Identification. Plants 2.5 – 7.0 cm high; herbaceous; caespitose. Fibrous roots and rhizomes present. Stems 0.5 – 5.0 cm long; erect; glabrous. Leaves basal; alternate; petiolate. Petioles 8 – 16 mm long; glabrous; adnate, with ocrea. Basal leaf blade 5 – 18 mm long, 5 – 20 mm wide; reniform or orbicular; bases cordate; thick; green or reddish; abaxial and adaxial surfaces both glabrous; margins glabrous; apices rounded. Inflorescences a racemiform or paniculiform cyme, with ≥ 30 pedicel- late flowers; 16 – 40 mm long. Tepals 4; 1.8 – 2.3 mm long, 1 – 2 mm wide; sepaloid; obovate or oblanceolate; green, red, or pink. Androecium with 5 – 7 stamens and 1.0 – 1.3 mm long anthers. Gynoecium with 2 styles and 1 stigma per style. Fruit an achene; 2.5 – 4.5 mm long, 2.5 – 3.5 mm wide; ovoid; winged; yellowish green to red; glabrous. Ranunculaceae – Buttercup family	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A272FFABFF2D6FCD3C365BD4.taxon	description	Figure 11 M	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A272FFABFF2D6FCD3C365BD4.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 26 ′ 40 ″ N, 062 ° 43 ′ 09 ″ W; 210 m a. s. l.; 14 Jul. 2019; habitat: mesic, with peat and till as substrates, dominated by Juncus biglumis, moss, and blue-green algae (macroscopic sheet colonies dominated by Nostoc sp.); QFA 0635516, CAN • same locality; 82 ° 27 ′ 49 ″ N, 062 ° 34 ′ 42 ″ W; 126 m a. s. l.; 25 Jul. 2019; hab- itat: wetland, with tussocks made of peat and till, dominated by Eriophorum triste, Arctagrostis latifolia, and Alopecurus magellanicus; QFA 0635588. Identification. Plants 3.5 – 13.0 cm high; herbaceous; caespitose. Fibrous roots present. Stems 1 – 10 cm long; erect, ascending, or semi-prostrate; glabrous. Leaves basal and cauline. Sheath margins glabrous. Ligules 0.9 – 1.3 mm long. Basal leaf blades 25 – 60 mm long, 0.7 – 1.1 mm wide; linear; folded or rolled in bud; abaxial and adaxial surfaces both glabrous; margins glabrous. Flag leaf blades 12 – 15 mm long, 0.9 – 1.1 mm wide. Inflorescence a dense or diffuse panicle; 18 – 35 mm long. Branches at lowest inflorescence node 4 – 6; 2 – 10 mm long. Pedicels glabrous. Spikelets 2.2 – 2.5 mm long, 0.8 – 1.2 mm wide. Florets per spikelet 1 – 3. First glumes 0.5 – 0.7 mm long; ovate; surface glabrous; margins glabrous; apices obtuse. Second glumes 0.8 – 1.1 mm long (shorter than the lowest floret); ovate; veins 1 – 3; surface glabrous; margins gla- brous; apices obtuse. Lemmas 2.0 – 2.3 mm long, 0.6 – 0.8 mm wide; lanceolate; rounded on the back; veins 3; surface dull, glabrous, and hairy, with hairs on and between the veins proximally; apices acute or erose, and glabrous; awnless. Palea 2.0 – 2.2 mm long; veins hairy. Rachilla between first and second lemmas 0.4 – 0.7 mm long. An- droecium with 3 stamens and 0.7 – 1.2 mm long anthers. Gynoecium with 2 styles. Fruit not seen at Alert. Characteristics allowing to distinguish × P. vacillans from Phippsia can be found under P. algida. Polygonaceae – Buckwheat family	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A24CFF95FF2D6C9B3C045B31.taxon	description	Figure 14 A	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A24CFF95FF2D6C9B3C045B31.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 27 ′ 54 ″ N, 062 ° 46 ′ 43 ″ W; 14 m a. s. l.; 8 Jul. 2019; habitat: wetland surrounded by hills, with silty sand as substrate, dominated by Alopecurus magel- lanicus; QFA 0634990. Identification. Plants 3 – 7 cm high; herbaceous; not caespitose. Fibrous roots present. Stems 2.5 – 6.0 cm long; erect or ascending; hairy, with hyaline hairs. Leaves basal and cauline; heterophyllous; alternate; petiolate (basal leaves) or sessile (cauline leaves). Petioles 5 – 14 mm long; glabrous. Basal leaf blades 6 – 10 mm long, 4 – 11 mm wide; widely depressed ovate or suborbicular; bases cuneate, obtuse, or truncate; lobed, with 3 – 5 main palmate, obtuse lobes; abaxial surface glarous or sparsely hairy, with hyaline hairs; adaxial surface glabrous; margins ciliate. Cauline leaf blades 6 – 9 mm long, 5 – 8 mm wide; lobed, with 3 deeply cleft, linear, obtuse lobes; abaxial surface glabrous; adaxial surface glabrous or sparsely hairy, with hyaline hairs; margins ciliate. Inflorescence a solitary flower. Sepals 5; 4 – 7 mm long, 2.0 – 3.5 mm; lan- ceolate, ovate, or obovate; pale brown or pinkish-brown, with hyaline margins; surface hairy, with hyaline hairs; margins glabrous or hairy; apices rounded or obtuse. Petals 5; 4 – 7 mm long, 2 – 4 mm wide; obovate; unlobed; yellowish-purple. Androecium with 20 – 30, 2.0 – 3.3 mm long stamens. Receptacle 3 – 6 mm high; surface glabrous or sparsely hairy, with hyaline hairs. Fruit an achene; 0.9 – 1.4 mm long, 0.7 – 1.0 mm wide; ovoid; yellowishgreen; with curved beak; glabrous. Ranunculus sabinei is similar to R. arcticus and R. pygmaeus, both of which are found on Ellesmere Island, by having white or translucent hairs on sepals, but differ in the following characters: leaf blades of R. sabinei and R. pygmaneus are usually 3 - lobed, whereas they are 5 - to 9 - lobed in R. arcticus; sepals of R. sabinei are bigger (4 – 7 mm long, 2 – 3 mm wide) than those of R. pygmaeus (2 – 4 mm long, 1.2 – 1.6 mm wide); and petals of R. sabinei are longer (5 – 8 mm long) than those of R. pygmaeus (1.2 – 3.5 mm long) but shorter than those of R. arcticus (7 – 15 mm long; Saarela et al. 2020).	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A24CFF94FF2D6A3B3F805E31.taxon	description	Figure 14 B	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A24CFF94FF2D6A3B3F805E31.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 25 ′ 52 ″ N, 062 ° 07 ′ 49 ″ W; 296 m a. s. l.; 16 Jul. 2019; habitat: wetland in a mountain pass, with peat and rocks as substrates, dominated by moss and Saxifraga cernua; QFA 0634989. Identification. Plants 4.0 – 13.5 cm high; herbaceous; caespitose or not caespitose. Fibrous roots present. Stems 3.2 – 11.0 cm long; erect or ascending; glabrous proximally and hairy apically, with brown hairs. Leaves basal and cauline; heterophyllous; alternate; petiolate (basal leaves) or sessile (cauline leaves). Petioles 8 – 25 mm long; hairy. Basal leaf blades 5 – 15 mm long, 8 – 16 mm wide; widely depressed ovate or suborbicular; bases cuneate or truncate; lobed, with 3 – 5 main palmate, obtuse lobes; abaxial and adaxial surfaces both either glabrous or sparsely hairy, with brown hairs; margins ciliate. Cauline leaf blades 5 – 15 mm long, 6 – 18 mm wide; palmatisect, with 3 – 5 linear, obtuse lobes; abaxial and adaxial surfaces both either glabrous or sparsely hairy, with brown hairs; margins ciliate. Inflorescence a soli- tary flower. Sepals 5; 3 – 6 mm long, 3 – 4 mm wide; ovate or obovate; yellowish-brown; surface hairy, with brown hairs; margins ciliate; apices rounded. Petals 5; 4 – 9 mm long, 3 – 7 mm wide; obovate; unlobed; yellow. Androecium with 20 – 30, 1.2 – 2.0 mm long stamens. Receptacle 3.5 – 7.0 mm high; surface hairy, with brown hairs. Fruit an achene; 1.5 – 3.0 mm long, 1.0 – 1.7 mm wide; ovoid; yellowish-green; with straight or curved beak; glabrous. Ranunculus sulphureus and R. nivalis have brown hairs on sepals in contrast to pubescent with white hairs or glabrous sepals found in the six other Ranunculus species present on Ellesmere Island (R. arcticus, R. aquatilis, R. hyperboreus, R. pygmaeus, R. sabinei, and R. subrigidus; Aiken et al. 2007; GBIF 2020). The two species can be differentiated by the following: the basal leaf blades are shallowly lobed in R. sulphureus, whereas they are 3 - parted in R. nivalis; and the receptacles are hairy in R. sulphureus and glabrous in R. nivalis (Saarela et al. 2020). Rosaceae – Rose family	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A24DFF94FF2D6F3A3EC65A43.taxon	description	Figure 15 A – C	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A24DFF94FF2D6F3A3EC65A43.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 28 ′ 34 ″ N, 062 ° 26 ′ 49 ″ W; 128 m a. s. l.; 2 Jul. 2019; habitat: barren ground, with till and rocks as substrates, and sparse dominance of Saxifraga oppositifolia; QFA 0635001. Identification. Plants 3 – 8 cm high; dwarf shrubs. Taproots and rhizomes present. Branches prostrate, sometimes rooting at nodes. Leaves evergreen; basal and cauline; isomorphic; alternate; petiolate. Stipules green or brown; hairy. Petioles 2 – 5 mm long; hairy, with white hairs. Leaf blades 4 – 9 mm long, 1 – 3 mm wide; lanceolate; bases cordate or truncate; unlobed; abaxial surface tomentose, with white hairs; adaxial surface shiny dark green, glabrous or sparsely hairy on the midvein; margins entire or slightly crenate, revolute, and glabrous; apices acute. Inflorescence a solitary flower. Pedicels 15 – 25 mm long; erect; hairy with woolly hyaline hairs and dark purple glandular hairs. Epicalyx absent. Sepals 7 or 8; 3 – 7 mm long, 1 – 2 mm wide; linear or lanceolate; dark green; surface hairy, with woolly hyaline hairs and dark purple glandular hairs; margins ciliate; apices acute. Petals 8; 7 – 11 mm long, 3 – 5 mm wide; obtrullate or obovate; unlobed; white or ivory. Androecium with 40 – 70 stamens and 0.5 – 0.9 mm long anthers. Gynoecium consisting of numerous separate carpels, with 5 – 6 mm long conical styles. Fruit an achene, with elongate plumose styles.	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A24DFF94FF2D6B083A7F5ABF.taxon	description	Figure 15 D, E	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A24DFF94FF2D6B083A7F5ABF.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 28 ′ 04 ″ N, 062 ° 51 ′ 28 ″ W; 31 m a. s. l.; 9 Jul. 2019; habitat: xeric in a slope, with till and rocks as substrates, dominated by Salix arctica and Dryas integrifolia; QFA 0635000. Identification. Plants 2.0 – 4.5 cm high; herbaceous; caespitose. Taproot and rhizomes present. Stems 2.0 – 5.5 cm long; ascending, decumbent, or prostrate; hairy, with non-glandular hairs. Leaves basal and cauline; heterophyllous; petiolate. Stipules green or reddish-brown; hairy. Petioles 5 – 28 mm long; hairy, with white nonglandular hairs. Basal leaf blades 10 – 25 mm long, 10 – 22 mm wide; pinnate-compound, with 3 – 5 pinnatisect leaflets distributed along the lower 2 / 3 of leaf axis. Leaflet blades 6 – 16 mm long, 4 – 9 mm wide; obovate; lobed, with 3 – 7 lanceolate, obtuse lobes; abaxial and adaxial surfaces both hairy, with white long – silky, non-glandular hairs (sometimes adaxial surface glabrate with few hairs); margins revolute and ciliate. Cauline leaf blades simple or ternate-compound. Inflorescence a solitary flower or a cyme, with 2 or 3 flowers. Epicalyx 1 – 3 mm long, 0.5 – 1.0 mm wide; oblanceolate. Sepals 5; 3 – 6 mm long, 2 – 3 mm wide; ovate; green; surface hairy, with hyaline non-glandular hairs; margins ciliate; apices acute. Petals 5; 3 – 6 mm long, 2 – 3 mm wide; obovate; unlobed, slightly lobed, or undulating; yellow. Androecium with 17 – 22 stamens and 0.4 – 0.6 mm long anthers. Gynoecium consisting of numerous separate carpels, with 0.9 – 1.2 mm long conical styles. Potentilla pulchella can be distinguished from the nine other Potentilla Linnaeus species present on Ellesmere Island (GBIF 2020) by the pinnate leaves (in contrast to ternate or palmate leaves in P. arenosa (Turczaninow) Juzepczuk subsp. arenosa and subsp. chamissonis (Hultén) Elven & D. F. Murray, P. hyparctica Malte subsp. hyparctica and subsp. elatior (Abromeit) Elven & D. F. Murray, P. nivea Linnaeus, P. subgorodkovii Jurtzev, P. tikhomirovii Jurtzev, P. vahliana Lehmann, and P. vulcanicola Juzepczuk; Ertter et al. 2014); the pinnate leaflets distributed along the 1 / 6 – 1 / 2 and more of the leaf axis (in contrast to 1 / 6 – 1 / 4 of the leaf axis in P. pedersenii (Rydberg) Rydberg and P. rubricaulis Lehmann; Ertter et al. 2014); and the ≤ 3 mm wide petals (in con- trast to all other Potentilla species present on Ellesmere Island, which have ≥ 3 mm wide petals; Ertter et al. 2014). At Alert, P. pulchella is highly polymorphic in terms of hairiness. Most individuals have silvery-white appearance due to dense hairs on leaves, whereas few individuals are sparsely hairy (Fig. 15 D, E). A molecular study of this species on Svalbard has shown that there is nearly no genetic (RAPD) variation among subpubescent and pubescent plants (Hansen et al. 2000). Instead, pubescence variation is phenotypic and is associated with different abiotic conditions: pubescent plants growing on cliffs, ridges, scree slopes, and silt shore terraces, and subpubescent plants on gravel shore terraces (Hansen et al. 2000). Salicaceae – Willow family	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A24DFF96FCAF6BA43ABF5D49.taxon	description	Figure 16 A – C	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A24DFF96FCAF6BA43ABF5D49.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 29 ′ 43 ″ N, 61 ° 57 ′ 15 ″ W; 14 m a. s. l.; 30 Jul. 2019; habitat: xeric in a slope, with till and rocks as substrates, and sparse dominance of Salix arctica; QFA 0635521. Identification. Plants 2 – 5 cm high; dwarf shrubs. Fibrous roots present. Branches erect, decumbent, or trailing; glabrous. Branchlets glabrous or hairy, with long hyaline hairs. Leaves deciduous; cauline; alternate; petiolate. Stipules 1.3 – 1.5 mm long; green; deciduous. Petioles 1.1 – 4.9 mm long; glabrous or hairy. Cauline leaf blades 5.6 – 19.5 mm long, 2.5 – 7.5 mm wide; elliptic, oblanceolate, or obovate; bases obtuse, cuneate, or rounded; green; abaxial surface glaucous and hairy, with long hyaline hairs; adaxial surface dull or shiny, and glabrous or sparsely hairy, with long hyaline hairs; margins entire, flat, and ciliate; apices obtuse or acute. In- florescences catkins. Plants dioecious. Peduncles hairy. Staminate catkins 14 – 25 mm long, 6 – 10 mm wide. Pistillate catkins 10 – 30 mm long, 8 – 14 mm wide; Bracteoles 0.8 – 1.6 mm long, 1.0 – 1.2 mm wide; reddish-brown or black; surface hairy, with white hairs; apices rounded or obtuse. Androecium with 2 stamens and 0.3 – 0.5 mm long anthers. Gynoecium with hairy (white hairs) pyriform ovaries (2.2 mm long, 1 mm wide), 1.1 – 1.3 mm long styles, and 0.3 – 0.6 mm long stigma lobes. Salix arctica and S. arctophila Cockerell ex A. Heller are the only Salix Linnaeus species present on Ellesmere Island (GBIF 2020) and can be distinguished based on the following: the largest medial leaf blade abaxial surface is glabrous in S. arctophila, whereas it is usually pilose in S. arctica (sometimes the midrib is sparsely short-silky and the apex is long-silky bearded; Saarela et al. 2020); leaf blade margins are serrulate or crenulate (sometimes entire) in S. arctophila, whereas the margins are entire in S. arctica (Saarela et al. 2020); and the ovary hairs are white and rust-couloured, appressed, crinkled, and ribbon-like in S. arctophila, whereas the hairs are only white, flattened, and wavy (not crinkled) in S. arctica (Aiken et al. 2007). Saxifragaceae – Saxifrage family	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A24FFF91FCAF6C023C1559BC.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 25 ′ 52 ″ N, 062 ° 07 ′ 49 ″ W; 296 m a. s. l.; 16 Jul. 2019; habitat: wetland in a mountain pass, with peat and rocks as substrates, dominated by moss and Saxifraga cernua; QFA 0634988. Identification. Plants 3 – 6 cm high; herbaceous; not caespitose. Fibrous roots present. Stems 1.9 – 5.0 cm long; erect; hairy, with septate glandular hairs (0.1 – 0.5 mm long). Leaves basal; patent or horizontal; alternate; petiolate. Petioles 0.5 – 3.0 mm long; hairy, with septate glandular hairs. Basal leaf blades 4 – 10 mm long, 3 – 7 mm wide; obovate or obtrullate; bases cuneate or attenuate; lobed, with 5 – 10 triangular, obtuse lobes; green or reddish-purple; abaxial and adaxial surfaces both glabrous; margins glabrous or ciliate, with septate glandular hairs. Inflorescence a solitary flower or a capitate cyme, with 2 – 5 flowers. Bracts 3 – 5 mm long, 1.2 – 2.5 mm wide; ovate or lanceolate; surface glabrous; margins ciliate. Pedicels hairy. Sepals 5; 3 – 5 mm long, 1.5 – 2.5 mm wide; elliptic or obovate; green to purple; surface glabrous; margins glabrous; apices obtuse or rounded. Petals 5; 2.5 – 4.0 mm long, 0.8 – 2.0 mm wide; obovate; unlobed; pink. Androecium with 8 – 10 stamens and 0.2 – 0.4 mm long anthers. Gynoecium with 2 styles. Four Micranthes Hawort species are present on Ellesmere Island (GBIF 2020). M. hieraciifolia (Waldstein & Kitaibel ex Willdenow) Haworth, M. nivalis (Linnaeus) Small, and M. tenuis have inflorescences without bulbils, in contrast to M. foliolosa (R. Brown) Gornall, which has bulbils replacing some or all the flowers (Saarela et al. 2020). The inflorescences, however, differ among the first three species; M. hieraciifolia has spikelike thyrses 2 – 10 cm long, whereas M. nivalis and M. tenuis have capitate thyrses or capitate cymes 0.5 – 4.0 cm long (Saarela et al. 2020). Micranthes tenuis is similar to M. nivalis but the two differ in a few characters: M. tenuis has more slender stems with sparse hairs <1 mm long, whereas stems of M. nivalis are pubescent with hairs> 1 mm long (Blondeau 2015 c); the inflorescence of M. tenuis is a solitary flower or an open capitate cyme with 2 – 10 distinctly pedicellate flowers, whereas inflorescence of M. nivalis is a compact capitate thyrse with 5 – 40 densely clustered flowers (Aiken et al. 2007; Brouillet and Elvander 2009 a). Moreover, M. nivalis is mostly found in barren grounds and hummocks, whereas M. tenuis is only found in wet and moist areas such as pond margins, wet meadows, and marshes (Aiken et al. 2007).	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A248FF91FF2D68AF3AF959F9.taxon	description	Figure 17 A, B	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A248FF91FF2D68AF3AF959F9.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 25 ′ 52 ″ N, 062 ° 07 ′ 49 ″ W; 296 m a. s. l.; 16 Jul. 2019; habitat: wetland in a mountain pass, with peat and rocks as substrates, dominated by moss and Saxifraga cernua; QFA 0635006. Identification. Plants 4 – 11 cm high; herbaceous; not caespitose. Fibrous roots present. Stems 3.5 – 10.0 cm long; erect or ascending; hairy, with septate glandular hairs. Leaves basal and cauline; heterophyllous; alternate; petiolate (basal and lower cauline leaves) or sessile (upper cauline leaves). Petioles 3 – 25 mm long; glabrous or hairy, with septate glandular hairs. Basal leaf blades 3 – 8 mm long, 3 – 11 mm wide; suborbicular or transversely elliptic; bases cuneate, truncate, or cordate; lobed, with 3 – 5 palmate, obtuse or acute lobes; green or reddish-purple; abaxial and adaxial surfaces both glabrous; margins glabrous or ciliate. Cauline leaf blades 2 – 10 mm long, 1 – 12 mm wide; ovate or lanceolate; unlobed or lobed, with 3 – 5 palmate lobes; abaxial surface hairy proximally, with septate glandular hairs; adaxial surface glabrous; margins glabrous or ciliate, with septate glandular hairs. Bulbils in cauline leaf axils 1 – 3 mm long; dark red. Inflorescence a solitary flower. Sepals 5; 2.5 – 4.0 mm long, 2 – 3 mm wide; ovate; reddish-purple; surface hairy, with septate glandular hairs; margins ciliate; apices obtuse. Petals 5; 5 – 10 mm long, 4 – 6 mm wide; obovate; unlobed or slightly notched; white or ivory. Androecium with 8 – 10 stamens and 0.7 – 1.8 mm long anthers. Gynoecium with 2 styles. Among the nine Saxifraga Linnaeus species present on Ellesmere Island (S. aizoides Linnaeus, S. flagel- laris Willdenow subsp. platysepala (Trautvetter) A. E. Porsild, S. hirculus Linnaeus, S. oppositifolia Linnaeus, S. cernua, S. cespitosa Linnaeus, S. hyperborea R. Brown, S. rivularis Linnaeus, and S. tricuspidata; GBIF 2020), only the five first species have toothed or lobed basal leaves with white, pale yellow, or purplish white petals (Aiken et al. 2007; Saarela et al. 2020). Among them, only S. cernua has bulbils (Aiken et al. 2007; Saarela et al. 2020). S. cespitosa has hairy adaxial leaf blade surface and hairy calyx, whereas these two sructures are glabrous in S. hyperborea, S. rivularis, and S. tricuspidata (Aiken et al. 2007). In addition, S. cespitosa and S. tricuspidata have sessile basal leaves, whereas S. hyperborea and S. rivularis have distinctly petiolate basal leaves (Saarela et al. 2020). Basal leaf blades are sharply 3 - toothed in S. tricuspidata, whereas S. hyperborea and S. rivularis have basal leaf blades with 2 – 7 rounded or obtuse lobes (Brouillet and Elvander 2009 b). The petals are also spotted in S. tricuspidata but not in S. cernua, S. cespitosa, S. flagellaris subsp. platysepala, S. hyperborea, S. oppositifolia, and S. rivularis (Aiken et al. 2007; Brouillet and Elvander 2009 b)	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A248FF90FCAF68F23A9D5BF7.taxon	description	Figure 17 C, D	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A248FF90FCAF68F23A9D5BF7.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 26 ′ 39 ″ N, 61 ° 57 ′ 18 ″ W; 159 m a. s. l.; 26 Jul. 2019; habitat: mesic, with till and rocks as substrates, dominated by Juncus biglumis, moss, and lichen; QFA 0635005. Identification. Plants 2.5 – 7.0 cm high; herbaceous; caespitose (cushion shape). Taproots and rhizomes present. Stems 1.5 – 6.0 cm long; erect or ascending; hairy, with glandular hairs. Leaves basal and cauline; heterophyllous; alternate; petiolate (basal leaves) or sessile (cauline leaves). Petioles 2 – 15 mm long; hairy, with glandular hairs. Basal leaf blades 3 – 7 mm long, 3 – 6 mm wide; oblanceolate or obtrullate; bases cuneate; lobed, with 3 linear or lanceolate, obtuse lobes; reddish-purple; abaxial surface sparsely hairy, with glandular hairs; adaxial surface glabrous; margins ciliate. Cauline leaf blades 3 – 6 mm long, 1 mm wide; linear or elliptic; abaxial and adaxial surfaces both sparsely hairy, with glandular hairs; margins ciliate. Inflorescence a solitary flower or a cyme, with 2 or 3 flowers. Pedicels hairy. Sepals 5; 4.0 – 5.5 mm long, 0.5 – 2.5 mm wide; ovate or lanceolate; purplish green or reddish-purple; surface hairy, with glandular hairs; margins ciliate; apices obtuse or rounded. Petals 5; 3.0 – 5.8 mm long, 1.2 – 2.5 mm wide; oblanceolate or obovate; unlobed; pale yellow. Androecium with 9 – 10 stamens and 0.3 – 0.8 mm long anthers. Gynoecium with 2 styles. Characteristics allowing to distinguish S. cespitosa from the other Saxifraga species present on Ellesmere Island can be found under S. cernua.	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A249FF93FCAF6AF43CE158AA.taxon	description	Figure 17 E	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A249FF93FCAF6AF43CE158AA.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 27 ′ 17 ″ N, 062 ° 35 ′ 55 ″ W; 166 m a. s. l.; 11 Jul. 2019; habitat: mesic in a slope; QFA 0635003. Identification. Plants 1.5 – 6.0 cm high; herbaceous; not caespitose. Fibrous roots and stolons present. Stolons 25 – 80 mm long; filiform; red; hairy, with glandu- lar hairs; leafless; terminating in a tiny rosette attached to the substrate by adventitious roots. Stems 1.0 – 5.5 cm long; erect; hairy, with glandular hairs. Leaves basal and cauline; heterophyllous; alternate; subsessile (basal leaves) or sessile (cauline leaves). Basal leaf blades 3 – 8 mm long, 2.0 – 4.5 mm wide; obovate or obtrullate; unlobed; red or green; abaxial and adaxial surfaces both glabrous; margins ciliate, with long stiff glandular hairs; apices obtuse. Cauline leaf blades 4 – 6 mm long, 1 – 2 mm wide; abaxial surface sparsely hairy, with glandular hairs; adaxial surface glabrous; margins ciliate; apices rounded or obtuse. Inflorescence a solitary flower. Se- pals 5; 3 – 6 mm long, 1.5 – 2.5 mm wide; ovate; green to purple; surface hairy, with glandular hairs; margins ciliate; apices obtuse. Petals 5; 4 – 10 mm long, 2.5 – 6.0 mm wide; obovate; unlobed; yellow. Androecium with 9 – 10 stamens and 0.5 – 0.9 mm long anthers. Gynoecium with 2 styles. Fruit not seen at Alert. Among the three Saxifraga species present on Ellesmere Island with entire basal leaves and yellow petals (S. aizoides, S. flagellaris subsp. platysepala, and S. hirculus; GBIF 2020; Saarela et al. 2020), S. flagellaris subsp. platysepala differs from the two others by having red, long stolons and unspotted petals (Saarela et al. 2020). S. aizoides and S. hirculus usually do not have stolons (but if present, the stolons are very short and green), but can have petals with orange spots (Saarela et al. 2020).	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A24AFF93FF2D69A13BA75C89.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 29 ′ 43 ″ N, 61 ° 57 ′ 15 ″ W; 14 m a. s. l.; 30 Jul. 2019; habitat: xeric in a slope, with till and rocks as substrates, and sparse dominance of Salix arctica; QFA 0635002. Identification. Plants 1.5 – 3.0 cm high; herbaceous; caespitose (cushion shape) or not caespitose (trailing shape). Taproots and rhizomes present. Stems 1 – 6 cm long; prostrate, decumbent, or ascending; hairy, with nonglandular hairs. Leaves cauline; sometimes overlapping or imbricate; decussate; subsessile. Cauline leaf blades 2 – 5 mm long, 1.0 – 4.5 mm wide; obovate or obtrullate; bases cuneate; unlobed; green; abaxial and adaxial surfaces both glabrous; margins ciliate, with non-glandular hairs; apices rounded, obtuse, or truncate. Inflorescence a solitary flower. Sepals 5; 2.5 – 5.0 mm long, 1.6 – 2.5 mm wide; ovate; purple; surface glabrous or hairy, with nonglandular hairs; margins ciliate; apices obtuse. Petals 5; 4 – 8 mm long, 3 – 5 mm wide; obovate; unlobed; purple, pink, or white. Androecium with 9 or 10 stamens and 0.2 – 0.6 mm long anthers. Gynoecium with 2 styles. Fruit a capsule. Saxifraga oppositifolia differs from all other Saxifraga species present on Ellesmere Island by having purple or pink petals (Aiken et al. 2007; Saarela et al. 2020).	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A24AFF93FCAF6C423AD9595E.taxon	description	Figure 17 G	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
7A1887E1A24AFF93FCAF6C423AD9595E.taxon	materials_examined	Materials examined. CANADA – Nunavut • Ellesmere Island, CFS Alert; 82 ° 26 ′ 39 ″ N, 61 ° 57 ′ 18 ″ W; 159 m a. s. l.; 26 Jul. 2019; habitat: mesic, with till and rocks as substrates, dominated by Juncus biglumis, moss, and lichen; QFA 0635004. Identification. Plants 3.5 – 7.5 cm high; herbaceous; caespitose (cushion shape). Taproots and rhizomes present. Stems 2.5 – 7.0 cm long; erect; hairy, with glandular hairs. Leaves basal and cauline; heterophyllous; alternate; subsessile (basal leaves) or sessile (cauline leaves). Basal leaf blades 3 – 10 mm long, 1.5 – 4.0 mm wide; linear or oblanceolate; bases cuneate; lobed, with 1 – 3 triangular, cuspidate lobes; green or red; abaxial and adaxial surfaces both glabrous; margins ciliate, with non-glandular hairs. Cauline leaf blades 2.5 – 6.5 mm long, 0.5 – 1.5 mm wide; elliptic or oblanceolate; unlobed or sometimes lobed, with narrow triangular lobes; abaxial and adaxial surfaces both glabrous; margins ciliate, with non-glandular hairs; apices cuspidate. Inflorescence a cyme, with 2 – 7 flowers. Pedicels hairy. Sepals 5; 1.5 – 2.0 mm long, 0.8 – 1.5 mm wide; ovate; green or purple; surface glabrous; margins glabrous; apices obtuse. Petals 5; 2.5 – 5.0 mm long, 1 – 3 mm wide; obovate or oblanceolate; unlobed; ivory or yellow, with apically yellow, orange, or red dots. Androecium with 10 stamens and 0.3 – 0.7 mm long anthers. Gynoecium with 2 styles. Characteristics allowing to distinguish S. tricuspidata from the other Saxifraga species present on Ellesmere Island can be found under S. cernua.	en	Desjardins, Émilie, Lai, Sandra, Payette, Serge, Dubé, Martin, Sokoloff, Paul C., St-Louis, Annie, Poulin, Marie-Pier, Legros, Jade, Sirois, Luc, Vézina, François, Tam, Andrew, Berteaux, Dominique (2021): Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List 17 (1): 181-225, DOI: 10.15560/17.1.181, URL: http://dx.doi.org/10.15560/17.1.181
