Plants slender, developing pseudobulbs, terrestrial or epiphytc. Leaves 1 or more, with sheathing petioles. Inflorescence ± dense, many-flowered. Flowers minute, mainly green or yellowish-green. Sepals and petals subequal in length, petals narrower Labellum adnate to the base of column, directed upwards by torsion of pedicel by 360˚, entire or lobed, ± excavated at base. Column short, fleshy, on either side with a short spreading wing or arm; anther terminal, ± incumbent; pollinia 4, cohering two by two, clavate, without caudicles or viscid glands; stigma entire. Ovary very small with long twisted pedicel.