Description from Flora of China
Acoridium Nees & Meyen; Platyclinis Bentham.
Herbs, epiphytic, lithophytic, rarely terrestrial. Rhizome short or long. Pseudobulbs tufted, fusiform or ovoid, narrow, l-leaved. Leaf blade linear to narrowly elliptic, leathery, usually petiolate. Inflorescence lateral, suberect to pendulous, slender, spicate or racemose, usually densely many flowered, synanthous (in Dendrochilum subg. Platyclinis (Bentham) Pfitzer) and heteranthous (in D. subg. Dendrochilum). Flowers usually resupinate, small, thinly textured. Sepals free, subequal, spreading; lateral sepals adnate to base of column. Petals smaller than sepals, often erose; lip 3-lobed or entire, usually with small lateral lobes and a large mid-lobe; disk 2- or 3-keeled. Column usually short, curved, foot absent or short (rarely long), with narrow or broad lateral arms (stelidia) and an often toothed apical wing around anther; pollinia 4, in 2 pairs, waxy, each pair with 1 slender caudicle; viscidium very small; stigma concave; rostellum ligulate, usually entire, spreading horizontally or ascending.
About 270 species: mainland Asia east to the Philippines and New Guinea, particularly well represented in the montane areas of Sumatra and Borneo; one species in China.
(Authors: Chen Xinqi (陈心启 Chen Sing-chi); Jeffrey J. Wood)