Polystachya sandersonii Harv.

Plants epiphytic, 80-200 mm tall; pseudobulbs adjacent, slender conical, 20-40 x 3-10 mm, sheaths decaying to fibres; leaves 2-4, erect, thin, flat, lorate, round to apiculate, sometimes obscurely and unevenly bilobed, 40-100 x 7-20 mm. Inflorescences scarcely taller than the leaves, 5-15-flowered, usually simple; peduncle and pedicels pubescent; bracts scarious, lanceolate, acuminate, 3-6 mm long. Flowers with brown sepals, brownish-yellow petals and a white lip. Sepals concave, shortly acuminate to apiculate; median triangular, 7-9 x 3.2-5 mm; laterals obliquely broadly ovate, 9-12 x 5-7.5 mm. Petals spathulate, subacute, 6.5-7 x 1.5-2.8 mm. Lip erect at the base, horizontal, 3-lobed, disc with a central colliculate-tuberculate ridge; midlobe oblong, hinged onto the disc, fleshy and smooth, acute and gradually decurved; side lobes porrect, rounded, 1.5-2 mm tall; mentum conical, 4-5 mm long. Gynostemium squat, 1.5 mm tall. Capsules cylinªdrical, 15 x 6 mm.