Herbs, epiphytic, rarely terrestrial, cespitose to climbing. Stems reduced [elongate], usually terminated with pseudobulb. Leaves 1-many; blade conduplicate, linear, lanceolate, or elliptic, margins entire. Inflorescences solitary flowers borne laterally within bract or leaf axil of rhizome of mature, immature, or apparently abortive shoots; floral bracts triangular, usually acute. Flowers: sepals and petals nearly same; dorsal sepal erect, concave; lateral sepals adnate to column foot; lip 3-lobed or simple; column not winged, semiterete, with foot at base; pollinia 4, waxy; stigmatic cavity round; rostellum not prominent. Fruits capsules, ellipsoid to obovoid.