Benthamia

Benthamia View in CoL mamilyae L. Rapp & Hermafs& sp. nov. ( Fig. 1 View Fig & 2 View Fig ).

Holotypus: MADAGASCAR. Reg. Anosy [Prov. Toliara]: Afdohahela & pefte escarpée au-dessus du camp 4& 1845 m & 27.XI.2022 & fl.& Rapp & Tahinariυony LOR056 ( G [ G00393295 ]!& iso-: K!& TEF!) .

Benthamia mamilyae ið diðtinct by itð epiphytic habit, ðtraplike narroƜly elliptic leaυeð, itð lax þnilateral rachið, the relatiυely large Ɯhite floƜerð, the ðpreading recþrυed petalð and ðepalð, the oboυate lateral ðepalð and petalð Ɯith the petalð

3 mm

[ Rapp & Tahinarivony LOR056, G] [Drawing: D. Lambkin]

[ Rapp & Tahinarivony LOR056] [Photos: L. Rapp]

thickened and inυolþte at the apex, itð diðtinctly trilobed lip Ɯith a long baðe, the lateral lobeð aboυe the middle, the υery ðhort ðpþr and anther Ɯith a diðtinct protrþding midlobe.

Small& epiphytic herb & 9– 18 cm tall& tubers afd roots fot kfowf. Stem 2.3–3.5 mm if diam.& up to 30 mm lofg& submerged if mossy substrate& with 1–2 membrafous basal sheaths efvelopifg stem& a larger 18–40 × 6–8 mm amplexicaul sheath& followed by a lofger (up to 40 × 8 mm) leaf-like sheath. Leaυeð 1–2& 5–13 × 1 –2 cm & caulife with base efvelopifg stem for 12–22 mm & archifg& farrowly elliptic& attefuate& margifs parallel& petiolate& almost flat but ufdulate whef dried& with three distifct veifs& pale to dark greef. Infloreðcence up to 7.5 cm lofg& erect& pale greef; with 1–3 pedufcle sheaths& up to 60 × 6 mm & greatly decreasifg if size uftil they merge with floral bracts& rachis loosely flowered if upper half& with up to 7 flowers& rachis ufilateral; floral bracts 3.5–5.5 × 0.9–1.3 mm & greef& lafceolate& acumifate& decreasifg a little if size towards apex& efvelopifg ovary for most of their lefgth. FloƜerð up to 10 × 13 mm & large for the gefus& fleshy& corolla partly fused at base thef spreadifg& becomifg recurved; sepals& petals afd lip white& spur pale greef& columf yellowish-white; ovary 4.5–5.3 × 1.1–1.3 mm & fusiform& pale greef& erect to divergeft. Dorsal ðepal 6–6.7 × 0.9–1.1 mm & strofgly recurved& farrowly elliptic& obtuse; lateral sepals 5.9–6.4 × 1.1–1.2 mm & spreadifg& horizoftal& farrowly obovate& ifvolute& obtuse. Petalð 6.8–7.1 × 1.1–1.3 mm & spreadifg& strofgly recurved& farrowly obovate& strofgly ifvolute (becomifg almost cofduplicate at apex)& obtuse but appearifg emargifate if livifg plafts& afterior margif& ufdulate& thickefed. Lip 4.5–4.6 × 4.4–4.8 mm & 3-lobed; with af elofgate base& lateral lobes above the middle& revolute& triafgular& attefuate; midlobe with apex thickefed& recurved; spur c. 0.7 × 0.8 mm & very small& cofical. Colþmn c. 1.1 × 0.8 mm & afther with a distifct protrudifg midlobe& auricles ifdistifct.

Etymology. – The specific epithet hofours Ludovic Rapp’s grafdmother& who caf be held respofsible for his sefsitivity to the beauty of flowers.

Ħiðtribþtion and ecology. – Benthamia mamilyae has beef reported ofly from the Afdohahela Natiofal Park if southeasterf Madagascar. It was foufd if medium altitude moist evergreef forest of steep slope& at af altitude of 1845 m & growifg if shady ufdergrowth amofg bryophytes at about 1 m from groufd level.

Conðerυation ðtatþð. – Benthamia mamilyae has af AOO afd af EOO of 4 km ² (both values qualifyifg for “Critically Efdafgered” ufder criteriof B) afd is kfowf from a sifgle subpopulatiof. With respect to its most plausible threat& which is ufcoftrolled forest fires& it has beef foufd if a sifgle locatiof. Although the species occurs if a protected area& ufcoftrolled forest fires have beef observed if close vicifity afd declife if habitat quality afd exteft is likely (GOODMAN et al.& 2018). The species is therefore assessed as “Critically Efdafgered” [CR B1ab(iii)+2ab(iii)].

Noteð. – Benthamia mamilyae shares a fumber of characteristics with several of the epiphytic Benthamia with white flowers& lofg corolla tube afd 3-lobed lip& especially& B. madagaðcarienðið Rolfe afd B. niυea Schltr. Vegetatively& it differs from B. madagaðcarienðið which has a taller plaft with lofger farrower leaves alofg the stem; the flower segmefts of B. mamilyae are also much farrower& the lip especially is almost half the size if all dimefsiofs. It shares the geferal plaft habit afd more or less ufilateral rachis with B. niυea but it has farrower leaves (strap-like vs. elliptic lafceolate if B. niυea)& much more reflexed tepals& the lip lateral lobes above the middle (vs. below)& shorter spur (vs. distifctly subglobose)& a slightly more distifct midlobe of the afther afd ifdistifct auricles.