Herbs, terrestrial to semiepiphytic, glabrous. Roots few, fibrous, 0.3-1 mm wide. Stems swollen at base into pseudobulb, ± globose, glabrous. Leaves 1-3(-5), with sheathing base; blade elliptic, ovate, or lanceolate. Inflorescences terminal, racemes, spicate racemes, corymbose racemes, or subumbellate racemes; floral bracts inconspicuous, lanceolate, subulate, or triangular-acuminate. Flowers 2-160, resupinate or not, erect or spreading, sessile or minutely to strongly pedicellate; sepals spreading, distinct or lateral sepals basally connate, ovate, elliptic, or lanceolate, 1-6 mm, margins revolute or not; petals spreading or recurved, filiform to linear, lanceolate, or triangular, usually much narrower than sepals; lip ovate or lanceolate, cordate, unlobed to 3-lobed, concave or saccate, widest proximal to middle, base auriculate or truncate; column free; anther terminal; pollinaria 4, waxy; 1 pollinarium or 2 separate hemipollinaria; viscidia yellow or orange. Fruits capsules; previous year´s fruiting stem and capsules frequently present during current year´s anthesis. x = 14, 15, 18, ca. 20, ca. 21, 22.