形态特征：Roots few, slender, often germinating from the junction between rhizome and inflorescence after flowering season. Rhizome tuberous, fusiform or cylindrical, 2-5(-7) cm × 3-10(-13) mm, yellowish brown, covered with root-hair-like unicellular hairs and verticillate scales. Scales lanceolate, pale yellowish brown, 1-3 mm. Inflorescence erect, 2-4 cm × 2-3 mm, pale brown underground, dark brown over ground, 3-4 noded, with tubular, membranous sheaths; rachis often less than 5 mm; floral bracts membranous, broad ovate to ovate, brownish, 5-9 × 4-6 mm; pedicel and ovary 5-15 mm. Flowers 1-3(-6), erect, tubular; all tepals connate and forming a 6-lobed perianth tube; perianth tube enclosed or rarely hardly opening, 4-5 mm in diam. Sepals similar, 9-13 mm, connate 3/5-2/3 their lengths with petals and lip; outer surfaces dark brown, densely verrucoulose; inner surfaces dark greenish brown,smooth, slightly concave at apex; margins entire; free lobe of dorsal sepal broad ovate, retuse, 3-4 × 4.5-6 mm; free lobes of lateral sepals deltoid, 4-5 × 4-5 mm. Petals light brown, obliquely ovate, concave, free lobes 3-3.5 × 2-3 mm; base contracted; margin slightly incurved, entire or scabrous. Lip adnate to perianth tube, light yellowish brown, ovate-deltoid, 3.5-4.5 × 3-4 mm, base contracted, petiole-like, margin entire or scabrous. Column straight, clavate, 5-6.5 × 2.5-3 mm, white tinged with grayish brown at base, with a pair of lateral wings (stelidia) and a prominent ventral appendage; column foot obscure; lateral wings reddish, incurved, edges parallel to column, tips inferior to anther; rostellum absent; stigma located near middle; ventral appendage reddish, arising just below stigma, apex parallel to column, rhombic-ovate, ca. 3 × 2.5 mm, bilobed at apex. Anther hemispheric, 1.1-1.3 × 0.8-1 mm; pollinia 2. Capsule cylindrical, 2-3.3 cm; pedicel elongate to 14-43 cm in fruit. Seeds fusiform, 1.5-2.2 mm.
