Description from Flora of China Herbs, epiphytic. Stems
pseudobulbous or caulescent, former 1-3-leaved, latter with up
to 12 leaves, very short or elongate. Leaves distichous or
arranged in a fan, erect to spreading, terminal, sometimes
fleshy, jointed on equitant sheaths, articulate. Inflorescences
lateral or arising from base of pseudobulb, racemose, laxly to
densely many flowered. Flowers resupinate, pale green or white,
minute, opening widely or not, often self-pollinating. Sepals
similar, free, sometimes connivent; lateral sepals often ±
adnate to column foot forming a mentum. Petals often smaller
than sepals; lip often with a basal claw attached to end of
column foot, base concave or ± saccate, margin entire or
obscurely 3-lobed. Column short, with a conspicuous foot; anther
terminal, obtuse at apex; pollinia 8, in 2 groups of 4, waxy,
attached by a narrow caudicle to a small viscidium. About 190
species: from Sri Lanka and mainland Asia, through SE Asia, to
Australia, New Guinea, and the Pacific island