Dendrobium denudans
Rare species
Epiphytic herb with smooth root. Flowering shoot erect, cylindric or narrowly fusiform, gradually reduce toward apex, base slightly contracted, become narrowed toward apex above middle, green or greenish-purple, 1.3-4 cm tall, internodes 3-9 mm long, 3-6 mm in diameter, fleshy, with 2-3 nodes, current stems enclosed in leaf sheaths, previous stems naked, with pinkish-purple line in longitudinal. Leaves 2-4 , distichous, alternate, papery, lowermost smaller than upper, mid-vien grooved above and ribbed below, glabrous on both sides, green or dull green above, light green or pale green beneath, ovate or lanceolate to oblong-lanceolate, apex unequally bi-lobe, each lobe acute, 1.5-4.1 cm long, 0.6-1.1 cm wide, base dilated into sheaths. Inflorescences raceme 1-3, subterminal or arising from upper part of current year’s leafy stem, suberect or nodding, 2.5-5.5 cm, much taller than leaves, with several to more than 10 small flowers; peduncle and rachis glabrous, light green or purplish-green, peduncle 0.6-2.6 cm long, rachis 2.2-4 cm long, covered with bracts; floral bracts slightly concave, glabrous on both sides, green or purplish-green, lanceolate to oblong-lanceolate, apex acuminate, base truncate, 1 veined, 2-4 mm long, 1-1.5 mm wide, margin entire, abaxial surface distingtly keeled. Flower papery, resupinate, waxy and polished, strong or faintly fragrant, long-lasting, up to ca. 6 mm in diameter; sepals and petals light green; mentum light green; labellum dull light green or stronger green ; column dull light green, foot green, lateral magins light green, stigmatic cavity light green, anther-cap light green, pollinia light yellow, pedicellate ovary green. Sapals spreading, often recurved distally, margin entire, abaxial surface distingtly keeled; dorsal sepal lanceolate, apex acuminate, base truncate, mid-vein grooved above, 1 vein, 3-4.2 mm long, 1-1.5 mm wide; lateral sepals obliquely triangular-lanceolate, apex acuminate, base obliquely truncate, 3 viened, hardly visible, 4-4.5 mm long, 1.9-2 mm wide. Mentum broadly conical, strainght or incurved distally, 0.8-1 mm long, ca.1-1.5 mm in diameter. Petals spreading, oblong or elliptic-oblong, margin entire, apex acuminate, base truncate, 1 vein, 3-3.5 mm long, 1-1.2 mm wide. Labellum recurved, elliptic without distinct sidelobe, apex acute, base truncate, margin entire, on inner surface 2 lateral keels raising somewhat laminate towards base ; disc thickened and fleshy, 2.8-3 mm long, 1.5-1.9 mm wide. Column short with strongly developed sidewings, 0.8-1 mm long, 1-1.5 mm wide at base; foot concave, stout at base, waxy, 0.5-0.6 long, 0.9-1 mm wide at base; stigmatic cavity circular or ovate, stelidia obtuse, anther cap subglobose or widely obovate, surface verrucose, adaxial side sulcate, apex emarginated, basal margin minutely ciliate, 0.3-0.5 mm long, 0.4-0.5 wide; pollinia 4, in 2 pairs, each pollinium narrowly elliptic, without caudicle and visidium. Ovary (including pedicel) narrowly clavate, curved, glabrous, somewhat waxy with 6-grooved, 0.8-1 mm long. Capsule dehiscent, green or dull green with pinkish-purple line in longitudinal, globose- ellipsoid with 3 obtuse keels, apex with persistant dried perianth, 3-5 mm long, 3-6 mm wide.
India, Nepal and Thailand
Epiphytic orhcid on tree
hills evergreen forest ; 1,860–1,870 m alt.