Small, epiphytic, monopodial herbs.Leaves distichous, ligulate to oblanceolate, often falcate, unequally 2-lobed at the apex.Inflorescences axillary, racemose, few- to many-flowered.Flowers small, white, green or yellow, with a relatively long pedicel.Bracts small, sheathing at the base.Lateral sepals often oblanceolate and asymmetric at the base, usually longer than the dorsal sepal.Petals usually smaller, triangular, often adnate to lateral sepals at the base.Lip entire or 3-lobed, ecallose, spurred.Column short; rostellum 3-lobed or bifid; pollinia 2, stipites 2; viscidia 2, rarely 1.