Description from Flora of China
Herbs, epiphytic, small, monopodial. Stems mostly short. Leaves few to ca. 10, ± distichous, flat, lorate, jointed and amplexicaul-sheathing at base, apex usually unequally bilobed. Inflorescences solitary to several, lateral or axillary, penetrating leaf sheaths, erect or pendulous, racemose, with a few to many spirally or distichously alternating flowers. Flowers usually resupinate, small. Sepals and petals free, spreading; lateral sepals often oblique and distinctly broader than petals, not adnate to column foot. Petals narrower than sepals; lip hinged to end of column foot by a movable joint, 3-lobed; lateral lobes erect, rather long; mid-lobe very short and small, fleshy, base spurred; spur or sac pointing forward in line with column foot, without interior ornaments, although front wall sometimes quite fleshy. Column short and stout, with a long foot; rostellum small, 2-lobed; pollinia 2, waxy, subglobose, cleft, attached by a common suboblong stipe to a ± triangular viscidium.
The genus Pteroceras has been monographed by Pedersen (Opera Bot. 117: 1-64. 1993).
Pteroceras simondianum (Gagnepain) Averyanov (Bot. Zhurn. (Moscow & Leningrad) 73: 432. 1988; Ornithochilus simondianus Gagnepain, Bull. Mus. Natl. Hist. Nat., sér. 2, 22: 632. 1951) was erroneously recorded from Yunnan by Y. M. Shui and W. H. Chen (Seed Pl. Karst Region China 1: 250. 2006). The record was based on a misidentified specimen.
About 20 species: from NE India to Indonesia (Maluku); two species (one endemic) in China.
(Authors: Chen Xinqi (陈心启 Chen Sing-chi); Jeffrey J. Wood)