Micropera mannii (Hook.f.) Tang & F.T.Wang (1951: 94)

Averyanov, Leonid V., Thai, Tran Huy, Nguyen, Van Canh, Truong, Ba Vuong, Maisak, Tatiana V., Doan, Nga Thi & Nguyen, Khang Sinh, 2022, New orchids in the flora of Vietnam (Orchidaceae, Aeridinae), Phytotaxa 572 (1), pp. 43-60 : 52-54

Micropera mannii (Hook.f.) Tang & F.T.Wang (1951: 94) ; Pearce, Cribb (2002: 531 fig. 118).

( Fig. 6A–D )

≡ Sarcochilus mannii Hooker (1890: 36) .

Type :— INDIA. India , Khasia Hills, 2–3000 ft. June 1878 Gustav Mann 11/80 (holotype K K000942449 ) .

≡ Camarotis mannii (Hook.f.) King, Pantling (1898: 239 tab. 317).

Description:— Herb monopodial perennial epiphytic. Stems rigid, pendulous, simple or few branching at the base, (6)8–10(12) cm long, covered by leaf sheaths throughout, leafy in apical half, with few light gray roots near base. Leaves sessile with distinct articulation at the base; leaf blade rigid, lanceolate, distinctly conduplicate, keeled below, gradually tapering to shortly bifid apex, (6)8–12(14) cm long, (0.8)0.9–1.1(1.2) cm wide. Inflorescences placed opposite leaf base, lax raceme, (5)6–10(12) cm long; peduncle straight to arching, 2–4 cm long, sheathed at base; rachis straight to distinctly zig-zag, with sparse brownish scurfy hairs, (2)4–6(8) cm long; floral bracts narrowly triangular, acute, 2.5–3 mm long. Flowers (9)9.5–10.5(11) mm across; sepals and petals white with purple tint to pale pink, with unclear irregular purple marks; lip white, base and side-lobes purple. Pedicel and ovary green, hairy with brownish scurfy hairs, (7)8–10(11) mm long, 0.8–1 mm in diameter. Sepals and petals narrowly obovate to oblong narrowly obovate, blunt to obtuse, spreading, (5)6–7(8) mm long, 1.2–1.8 mm wide, lateral sepals shortly connate with lip base, petals little narrower. Lip obscurely 3-lobe, fleshy, narrowly obovoid, bailer-shaped in outline, (4)4.5–5.5(6) mm long, narrowing to the base, distally broadening, deeply saccate, at right angle to the ovary; side-lobes obliquely truncate, erect, with incurved front corner; median lobe minute, broadly triangular. Column foot-less, 1.4–1.6 mm tall, twisted, with large narrowly triangular oblique rostellum. Anther cap hemispheric, 0.6–0.7 mm in diameter. Fruits unknown.

Ecology and phenology:—Epiphyte in lowland evergreen broad-leaved forests. Flowers in May–June.

Distribution:— VIETNAM (Dak Lak Province). Bhutan, India (Assam, Meghalaya, Nagaland, Arunachal Pradesh, Sikkim, West Bengal).

Conservation status:—Vietnamese population of this rare species is distant from its nearest location in NE India for about 2500 km, which considerably expands EOO. Meanwhile, the species was not ever reported on vast areas between newly discovered location in Vietnam and main species area in Bhutan and NE India. In this connection, it may represents isolated disjunctive refuge do not connected directly with main species area. According to available data, lone population in Vietnam has AOO surely less than 10 km 2 with the number of mature individuals less than 50. Being into consideration the extensive deforestation in the region of species location its conservation status should be preliminarily estimated as nationally Critically Endangered, CR (B1a,b(i-v); C2a(i); D).

Notes:—In comparison with plants from Bhutan and NE India, studied Vietnamese specimens have somewhat larger leaves, longer inflorescences, and distinctly larger flowers. Additionally, they are isolated geographically hence may represent separate allopatric variety.

Studied specimens:— VIETNAM, herbarium specimen prepared in 29 May 2022, L. Averyanov , N. V. Canh, T. Maisak , AL 1339 from cultivated, wild collected plants originated from Dak Lak Province, flowers pink, tepals with purple marks, lip base and side-lobes purple, column purple, anther pale yellow ( LE01168977 https://herbariumle. ru/?t=occ&id=142645 analytical photos LE01123411 https://en.herbariumle.ru/?t=occ&id=137201) .

Figures

FIGURE 6. Micropera mannii (Hook.f.) Tang & F.T.Wang. A. Flowering plant.B. Inflorescences. C. Flowers, anther cap and pollinarium removed. D. Intact flower, half side view. Specimen L. Averyanov, N.V. Canh, T. Maisak, AL 1339. Trichoglottis ramosa (Lindl.) Senghas. E. Flowering plant. F. Flattened plant. G. Intact flowers. H. Flower and flower buds. I. Intact flower frontal view. J. Flower with anther cap removed, frontal view. Specimen L. Averyanov, N.V. Canh, T. Maisak AL 1378. All photos made by L.Averyanov; correction and plate design by L. Averyanov and T. Maisak.