Ritaia King & Pantling.

Herbs, epiphytic or lithophytic. Rhizome short or rather long, creeping or pendulous; roots fibrous. Stems simple or branched, tufted, sometimes terete and rushlike, 1-leaved, with thin, brown, often reticulate basal sheaths, sometimes entirely covered by membranous, reddish brown sheaths, pseudobulbs absent. Leaves borne at apex of stem or branches, usually linear, narrowly lanceolate, or subcylindric, leathery, fleshy or subterete, rarely thinly textured, base articulate. Inflorescence terminal, usually with several clustered flowers, rarely reduced to a solitary flower. Flowers resupinate, small, rarely large and showy. Sepals similar, erect, connivent; lateral sepals adnate at base to column foot forming a saccate or spurlike mentum, enclosing basal part of lip. Petals narrower than sepals; lip adnate to apex of column foot by a long incumbent claw, slightly or partly thickened, spurless, entire or inconspicuously 3-lobed, usually with longitudinal calli. Column short, dilated above, apex bilobed or with 2 spatulate erect arms, foot long; anther terminal, incumbent; pollinia 8, in 2 groups, waxy, sessile, commonly adhering to a small viscidium.

About 100 species: tropical Asia to New Guinea and the Pacific islands; three species (one endemic) in China.

(Authors: Chen Xinqi (陈心启 Chen Sing-chi); Jeffrey J. Wood)