Epiphyte; pseudobulbs ovoid, 4.5-6.5 cm long, to 3.5 cm wide, dark brown, strongly ridged, enveloped at base by fibrous, imbricating bracts, bearing 2 or 3 terminal leaves. Leaves +/- lance-elliptic, usually acuminate, plicate, 25-50 cm long, 5-12 cm wide, moderately thin. Racemes +/- pendulous from base of pseudobulb, 30-60 cm long; flowers numerous (to 30), well spaced, grotesque, strongly fragrant, with all parts yellow and spotted or banded with reddish-brown, mostly membranaceous; pedicels slender, 2-3.5 cm long; dorsal sepal lanceolate, acuminate, to 1.8 cm long, free and erect, inserted about midway on the column, the lateral sepals strongly reflexed, obliquely ovate, acuminate, to 2.5 cm long, inserted on the column foot; petals slender, acuminate, to 8 mm long, inserted on column and fused at base to lateral sepals; lip fleshy, clawed, complexly bipartite, 1.5-2.5 cm long, with 2 slender, lateral, +/- recurved projections from base and with 2 slender, erect, lateral antennae nearer the apex; column erect, +/- arcuate, 1.5-2 cm long. Fruits not seen. Dressler 2858. Apparently rare on BCI. Reportedly flowering irregularly more than once a year (Powell 76). Flowers principally in the dry season, but may flower in the early rainy season (to July) as well. The fruits apparently develop quickly and disperse their seeds chiefly in the dry season. BCI plants are pollinated by the bee Euglossa tridentata Mourre, but have also attracted E. cordata, E. townsendii, E. hemichlora, and E. cyanaspis ( Dressler, 1968a; Baker, 1963).