P. acrisepalaAmes & Schweinf. Caespitose epiphyte; pseudobulbs lacking; stems very short, each bearing a single leaf. Leaves +/- oblanceolate, obtuse or acute, 1.5-9 cm long, the veins obscure except the midrib, the base ensheathed in slender, scarious bracts. Flowers 1 to few in terminal fascicles borne on slender peduncles usually above the leaves; peduncles usually persisting; sepals acute, maroon, fused at base, 7-9 mm long, the lateral sepals united to the middle or beyond; petals 2-3.5 mm long, solid maroon, the apex pointed; lip narrow, 2-4 mm long, l-2 mm wide, lighter and papillate at apex, the margin ciliate, auriculate on both sides. Fruits ellipsoid, to 1 cm long, green or olive, tinged or striped with purple. Croat 9787.