Pterygodium acutifolium Lindl.

Plants slender, to 470 mm; leaves 3-4, spaced up the stem, oblong, subapiculate, to 180 x 23 mm. Inflorescences lax to subdense, to 70 mm long, 1-14-flowered; bracts ovate-acute. Flowers c. 17 x 15 mm, sepals lime-green, petals and lip rich yellow; ovaries c. 20 mm. Sepals acute; median sepal saccate, 8-12 x 4-5 mm, adnate to the petals; lateral sepals spreading, saccate, 10-12 x 5-6 mm. Petals obliquely broadly oblong, apiculate, shalªlowly concave, c. 12-13 x 8-10 mm. Lip deltate, acute, c. 5 x 3-4 mm, margin undulate; appendage triangular, apex smooth and down-curved, c. 7-10 x 4 mm. Stigma lobes elliptic, c. 2 mm long, at the base of the lip appendage posteriorly; rostellum c. 2 mm tall, arms c. 3 mm long.