Compilation
Polystachya mayombensis

Epiphytic or lithophytic herb to c. 45 cm high.Pseudobulbs clustered, 2–6 × 0.5–1 cm, conical or oblong, 2–4-leaved.Leaves ± distichous, 5–17 × 0.5–2 cm, ligulate, conduplicate, fleshy, unequally 2-lobed at the apex, the lobes rounded.Inflorescence (floral axis) to c. 40 cm long, branched; the branches secund, fairly short, pubescent, densely many-flowered.Peduncle covered with bilaterally flattened, imbricate sheaths.Pedicel and ovary c. 3 mm long.Flowers bright yellow, yellow-green or brownish-cream.Dorsal sepal 1.5–2.8 × 0.7–1.5 mm, ovate, acute or apiculate; lateral sepals 2.2–3.6 × 1.2–2.4 mm, obliquely ovate; mentum conical or rounded, c. 2 mm high.Petals 1–2.6 × 0.3–0.5 mm, oblanceolate.Lip 2.2–3 × 1.7–2.5 mm, clawed at the base, 3-lobed about the middle; mid-lobe 1.3–1.4 × 1.3–1.4 mm, ± orbicular, emarginate; side lobes porrect, shorter than the mid-lobe, rounded at apex; disk with a cushion of farinaceous hairs towards the base.Column less than 1 mm long.