Glabrous epiphytic rarely lithophytic herb, forming clumps.Pseudobulbs 1.5–18 cm tall, 0.3–1.2 cm wide at base, conical or cylindrical, covered with membranous sheaths when young, 1-leafed.Leaf 3–21(36) × 1.2–5.5 cm, ovate, obovate or elliptic, acute or apiculate, often undulate on the margin, auriculate at base, articulated 2–6 mm above the apex of the pseudobulb.Inflorescence (floral axis) usually longer than the leaf, erect or arching, 5–30 cm long, usually branched, densely many-flowered.Flowers white or yellow-green (outside the Flora Zambesiaca area they may be pink or purple).Pedicel and ovary 6 mm long; bracts 2.5–5 mm long, ovate-triangular, acuminate.Dorsal sepal 4–8 × 2–4.5 mm, ovate, acute; lateral sepals 5–8 × 3–6 mm, obliquely triangular, apiculate, slightly keeled on the outside, forming with the column foot a conical mentum up to 7 mm high. Petals 3.5–7.5 × 1–2.5 mm, linear to oblanceolate.Lip 4–7.8 × 3–6 mm, recurved, 3-lobed in the apical half, with a yellowish, fleshy central callus; mid-lobe c. 3 × 2 mm, subquadrate, apiculate; side lobes porrect, rounded.Column 0.5–3.5 mm long.