Fagopyrum urophyllum (Bureau & Franch.) H.Gross, Bull. Géogr. Bot.

Fagopyrum urophyllum (Bureau & Franch.) H.Gross, Bull. Géogr. Bot. View in CoL 23: 21. 1913. Polygonum urophyllum Bureau & Franch., J. Bot. View in CoL (Morot) 5(10): 150. 1891.

Lectotype (designated here): CHINA, Se-tchuen ( Sichuan) province, around Ta-Tsien-Lou, s.d., Prince Henri d’Orléans, collected during the trip of M. Bonvalot and Prince Henri d’Orléans ( Voyage de M. Bonvalot et du Prince Henri d’Orléans à travers l’Asie), s.n. ( P [ P04963938 digital image!); isolecto P [ P04963934 digital image!]). FigS. 1 View Fig & 2 View Fig

Perennial undershrubs. Stems 60–90 cm long, simple, terete, sub-erect, brownish, much branched, 2–3 mm in diam., glabrous, finely striate, slightly woody; internodes 3.5–7 cm long, upper half of stems with shorter internode than lower half, reddish brown to green, finely pubescent at nodes. Ochrea membranous, tubular, 5–9 mm long, oblique at mouth, eciliate, prominently veined, glabrous, brown. Petioles 2–6 cm long, terete, densely pubescent, greenish. Leaves deltoid to hastate, 2–8 × 1.5–4 cm, broadly sagittate at base, margin entire, attenuate to long acuminate at apex (acumen 1–2 cm long), coriaceous; upper surface dark green, glaucescent, midrib prominent, minutely pubescent along veins, otherwise glabrous; lower surface light green, densely pubescent along veins, usually with whitish hair; lateral veins 6–7 pairs, palmately arranged; Inflorescence terminal, lax spreading branched panicles, 7–20 cm long; peduncle minutely pubescent, rarely glandular, 5–12 cm long; bracts greenish, narrowly funnel-shaped, 2–3 mm, apex acute to shortly acuminate, entire, glabrous, each 3 to 4-flowered. Pedicels 3–4 mm long, slender, glabrous, articulate at apex. Flower pentamerous, 2.5–4.5 mm long. Perianth lobes (tepals) 5, white, in two whorls, elliptic or elliptic-oblong, 2–3 × 1.5– 2 mm, obtuse at apex, margins entire, persistent. Stamens 8, alternating with yellowish glandular discs; filaments unequal, 1.5–2 mm long, glabrous; anthers purple, 0.5–1 mm long, dorsifixed, dehiscence longitudinally. Ovary superior, trigonous, 0.5–0.8 mm long; styles 3, free, 0.7–1 mm long; stigmas capitate. Achenes broadly ovoid, abruptly trigonous, 3–4 × 1.5–2 mm, much exceeding or equalling the persistent perianth, black-brown, glabrous.

Flowering & fruiting: Flowering from June to August; fruiting from July to November.

Habitat: Scatterley grows on gravelly hill slopes, forest margins, footpaths, brushes in valleys; at an elevation range of 1500–2200 m.

Distribution: INDIA: Namchi, Tendong Reserve, South district, Sikkim. CHINA: South and Central.

Specimens examined: INDIA, Sikkim, South district, near Namchi, N 27̊92 57.543, E 88̊222 8.463, 1848.5 m, 24.10.2020, M.Das & S.S.Dash 84754 (CAL); Ibid., N 27̊92 26.13, E 88̊252 133, 1801 m, 24.10.2020, M.Das & S.S.Dash 84758; near Tendong, N 27̊122 6.623, E 88̊232 463, 1785 m, 24.10.2020, M.Das & S.S.Dash 84755 (CAL); Namchi, 06.08.2000, B.K.Shukla 23548; Ibid., 06.08.2000, B.K.Shukla 23540; Tendong R.F., 17.08.1985, A.K.Verma 3785 (BSHC).

Conservation status: During our studies, we were able to locate eight populations of Fagopyrum urophyllum in Namchi South district, Sikkim and its surrounding areas (GPS coordinates: N 27̊92 57.543, E 88̊222 8.463; N 27̊122 6.623, E 88̊232 463; N 27̊92 26.13, E 88̊252 133; N 27̊92 28.633, E 88̊252 23; N 27̊92 54.133, E 88̊212 513; N 27̊92 39.13, E 88̊242 243; N 27̊102 1.763, E 88̊212 543; N 27̊122 23.243, E 88̊242 28.913.) ( Fig. 3 View Fig ). Each population consisted of 5– 10 mature plants in various flowering stages. According to the GPS coordinates, the extent of occurrence (EOO) of the species F. urophyllum was calculated to be 16.5 km 2, and the area of occupancy (AOO) 24 km 2. While calculating the EOO and AOO we have also taken into consideration earlier collections. The species is dwindling in its natural habitat due to severe habitat fragmentation and vulnerable because of its low density of adult plants. Moreover, the natural habitats of the species are under continuous pressure from various developmental activities in the region, such as road construction, Building construction etc. Other possible threats are land clearance for agriculture expansion, high grazing and forest fires. Since no data on the population sizes of previous collections were available, we only used the geographic coordinates of the collected localities to estimate the geographic range of this species ( Moat, 2007) through the Conservation Assessment Tool GeoCAT. With the currently available information, the threat status for Fagopyrum urophyllum in India has been assessed as ‘Critically Endangered’ [CR B1ab(iii)+2ab(iii);].

Notes: This species was initially placed in section Tiniaria of genus Fagopyrum ( Gross, 1913) , but later Steward (1930) treated it under section Fagopyrum of genus Polygonum . Haraldson (1978) elevated section Fagopyrum to generic rank. The species also shows similarity in leaf characteristics with Fallopia convolvulus (L.) Love. Fagopyrum urophyllum can be easily differentiated from its allied species by its shrubby habit, broadly sagittate leaves with long acuminate or caudate apex.