Epiphytic herbs with very strongly compressed, exceptionally thin, ovate-elliptic or oblong-elliptic, usually smooth pseudobulbs 6-10 cm. tall and 3-6 cm. wide, the apices with 1 or infrequently 2 leaves, the bases with several distichously imbricating bracts the uppermost 2-3 of which are conspicuously foliaceous. Leaves lanceolate to elliptic-lanceolate, subacute to obtuse, pergameneous, 15-33 cm. long and 2.5-5.5 cm. wide. Inflorescences 1 or 2 erect or arching panicles, usually much exceeding the leaves, up to about 1 m. in length, produced from the lateral bases of the pseudobulbs. Flowers of moderate size, averaging about 3 cm. in diameter, the sepals and petals brown, sometimes with yellow margins and apices, the mid-lobe and lateral lobes of the lip bright yellow, the central isthmus brown with a bright yellow crest. Sepals subequal, free, spreading, elliptic-lanceolate, obtuse to acute, with strongly undulate margins, 1.2-1.7 cm. long and 0.4-0.6 cm. wide. Petals somewhat broader than the sepals, spreading, elliptic-oblong, obtuse to subacute, with undulate margins, 1.4-1.6 cm. long and 0.5-0.65 cm. wide. Lip pandurate, 3-lobed, 1.4-1.6 cm. long and 1-1.5 cm. broad at the trans-versely reniform, emarginate apex, the mid-section of the lip abruptly contracted in front into a broad isthmus, the basal portions more or less confluent with the short, suborbicular, lateral lobes, the disk with a 5-lobed puberulous crest, termi-nating in a central porrect tooth. Column short, 4-6 mm. long, the apex with dolabriform wings.
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