Description from Flora of China
Herbs, epiphytic, medium-sized, coarse, monopodial, with many thick roots. Stems ascending, short to elongate, often stout, enclosed by leaf sheaths, with many nodes, leafy. Leaves distichous, linear-oblong to terete, leathery, slightly fleshy, base jointed and sheathing, apex bilobed. Inflorescence lateral, pendulous, variable, racemose or paniculate, usually densely many flowered. Flowers showy, medium-sized. Sepals and petals similar, broad, spreading; lateral sepals decurrent on column foot. Petals smaller than sepals; lip attached to end of column foot, usually immovable, spurred, 3-lobed; lateral lobes decurrent on column, erect; mid-lobe large or small, often erose; spur narrowly conic or horn-shaped, bent forward, usually with swellings or calli inside. Column elongate, often broadened at apex, with a short or long foot; rostellum short or long, bifid; anther 2-locular, ± beaked; pollinia waxy, 2, subglobose, grooved, attached by a long, slender stipe to a solitary, semicircular viscidium.
About 20 species: Sri Lanka, India, Nepal, Bhutan, Myanmar, China, Thailand, Indochina, and Malaysia to the Philippines and Indonesia; five species (one endemic) in China.
(Authors: Chen Xinqi (陈心启 Chen Sing-chi); Jeffrey J. Wood)