形态特征：Stems slender, terete, pendulous, 40-70 cm long, 4-7 mm in diam., leafy in upper part, the internodes cylindrical, 2-5 cm long, yellowish green. Leaves linear-lanceolate, about 5.5-10 cm long, 6-8 mm wide, apex acute to obtuse, base rounded. Flowers 1-3, often 2, borne from the upper nodes of stems, usually pale yellow, rarely white, bracts 2-3, imbricate, ovate-triangular, 3-6 mm long, opening up to about 3-4 cm in diameter; dorsal sepals lanceolate, 3-4 cm long, 3.5-4 mm wide, apex acute, lateral sepals similar to dorsal one, base adnate to foot of column forming a mentum 9-12 mm long; petals lanceolate, as long as dorsal petal, apex acute, claw at base; lip oblong-lanceolate, about 2.5 cm long, apex acute, with two keels at the middle of the basal lip, pilose; column ca. 2 mm long, foot 8-10 mm long, concave; anther hood-like, 1.5 mm long; pollinia 1 mm long.
