Trichoglottis ramosa (Lindl.) Senghas

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 : 58

Trichoglottis ramosa (Lindl.) Senghas in Schlechter (1988: 1315)

( Figs. 6E–J )

≡ Saccolabium ramosum Lindley (1833: 224) .

Type :— BANGLADESH, “Deltae Gangeticae”, Wallich icon 654 (holotype K, fide Pearce, Cribb 2002: 561) .

≡ Staurochilus ramosus (Lindl.) Seidenfaden (1988: 95) , Pearce, Cribb (2002: 561 fig. 129).

Description:— Herb monopodial perennial epiphytic. Stems rigid, ascending, simple or few branching at the base, (4)5–7(8) cm long, covered by leaf sheaths throughout, leafy in apical half, with few thick white roots near base. Leaves sessile with distinct articulation at the base; leaf blade rigid, lorate, distinctly conduplicate, keeled below, arching, with shortly bifid apex, (6)10–16(18) cm long, (0.5)0.6–1.1(1.2) cm wide. Inflorescences axillary, many branched, erect or spreading horizontally, lax panicle, (4)6–24(26) cm long; peduncle 0.5–1(1.5) cm long, sheathed at base; branches (2)3–9(11) cm long, branching, rachis slightly zig-zag, (0.5)1–6(8) cm long; floral bracts brownish, broadly ovate, blunt to obtuse, 0.5–0.7 mm long. Flowers (5)5.5–6(6.5) mm across; sepals and petals white brown orange with pale yellow at base and apex; lip white with purple tint at center, later pale yellowish; column brown orange; anther cap and pollinaria light yellowish. Pedicel and ovary olive greenish, (3.5)4–5(5.5) mm long, 0.8–1 mm in diameter. Sepals and petals narrowly obovate to oblong narrowly obovate, blunt to obtuse, spreading, (2.5)2.7–3(3.2) mm long, (0.7)0.8–1(1.1) mm wide, petals narrower and slightly oblique. Lip spurred, 3-lobe, fleshy, (3.6)3.8–4(4.2) mm long from lip to apex of spur; side-lobes rectangular, erect, slightly pointed at front, densely hairy with stiff white hairs; median lobe broadly triangular, 3-lobulate, lateral lobules small, ovate triangular, median lobule twice larger, broadly ovate, round at apex; spur narrowly conoid, 1.5–1.7 mm long. Column foot-less, glabrous, short and stout, 0.6–0.7 mm tall and wide, with round concave stigma at front. Anther cap hemispheric, 0.6–0.7 mm in diameter, shortly beaked. Pollinarium stipe slender with small round viscidium, pollinia 2, globular, incompletely divided into 2 unequal hemispherical bodies. Fruits fusiform, shortly stalked, about 2 cm long.

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

Distribution:— VIETNAM (Kon Tum Province), NE India, Bangladesh, Myanmar, Thailand.

Conservation status:—The discovered location of the species in Vietnam near the border of Laos is not much surprising and actually is allied to main species territory spreading from NE India to Thailand. Meanwhile, it expands the species distribution area on more than 200 km in the E direction. The lone discovered population has AOO surely less than 10 km 2 with the number of mature individuals less than 50, decreasing due to deforestation of habitat. According to available data the conservation species status in both countries may be estimated as nationally Critically Endangered, CR (B2a,b(i-v); C2a(i); D).

Notes:—The species was discovered in Vietnam very close to the border of Laos and may be surely found in this country in Attapu Province. Studied specimens differ from “western” plants in glabrous column (vs. column at front shortly hairy), obtuse lip median lobe (vs. lip apex emarginate), slightly larger flowers and little different flower color scheme (figs. 6E-J). They may represent a separate variety or even new, not yet described species, study of which needs more collections.

Studied specimens:— VIETNAM, herbarium specimen prepared in 01 June 2022, L. Averyanov , N. V. Canh, T. Maisak AL 1378 from cultivated, wild collected plants originated probably from the border area between Kon Tum (Vietnam) and Attapu (Laos) provinces, N. X. Son s.n., epiphyte, sepals and petals orange, lip white ( LE01168932 https:// en.herbariumle.ru/?t=occ&id=139795, analytical photos LE01123456 https://en.herbariumle.ru/?t=occ&id=137246) .

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.