Plants up to about 95 cm tall. Leaves 3–10, clustered at or near the base, long-petiolate; petiole up to 11 cm long, channeled; blade up to 13 cm long and 5.7 cm wide, ovate or ovate-lanceolate to elliptic, acute or acuminate, more or less cuneate below, often oblique, glabrous. Peduncle erect, very sparsely pilose below, more densely above, provided with about 3 distant, tubular sheaths of which the lowest is foliaceous, terminated by a loosely or densely several- to many-flowered raceme about 7–25 cm long. Flowers carmine and yellow, sepals glandular-pubescent. Floral bracts 8–15 mm long, lanceolate, ovate-lanceolate or elliptic-lanceolate, acuminate, glandular-pubescent. Pedicellate ovary 11–15 mm long, glandular-pubescent. Dorsal sepal 7.5–10 mm long, 1.5–3 mm wide, linear-lanceolate to oblong lanceolate, acute to acuminate, 3- or 5-veined. Petals unguiculate, claw free part ca one mm long; blade four to eight mm long in total, 1–2.5 mm wide, obliquely ovate-elliptic to ligulate-ovate, rounded to obtuse at apex, elongate basally into a long narrowly ligulate, blunt and somewhat twisted auricle, veins 2, branching. Lateral sepals 8–11 mm long, 4–5.2 mm wide, obliquely elliptic-obovate to elliptic, acute, several-veined. Lip unguiculate; claw less than one mm long, with a prominent, bilobed callus at base; lamina ca two to three mm long in total, up to 1.3 mm wide, lanceolate, thick, with a prominent bidentate, upcurved callus below apex, apex hooked,ovate to lanceolate, attenuate, obtuse to subacute. Gynostemium up to four mm long,clavate, long-stalked (Figs. 22 and 23). Ecology: Terrestrial in humid forest. Flowering throughout the year. Distribution: The Greater Antilles (Cuba, Jamaica), Peru, Ecuador, Colombia, Venezuela. Alt. 1,350–3,000 m. The occurrence of this species in Ecuador was reported by Garay (1978: 217) and from Venezuela by Carnevali et al. (in Hokche, Berry & Huber, 2008
Notes: This is the most widespread species of the genus known in the study area and a morphological variation between populations is observed (Figs. 22 and 23). However, P. diptera can be easily distinguished from other species by presence of the obliquely ovate-elliptic petals which are basally elongate into long narrowly ligulate, blunt and somewhat twisted auricle as well as by the narrow, thick lip adorned with two digitate projections at base and unequally 3-dentate apex. Garay (1978: 217) synonymized under this name P. elata from Colombia. According to Schlechter (1920) and this study, however, P. elata can be easily separated from P. diptera by having non-twisted auricle of petal and lip with different calli. Calli consists of a single, acute, upcurved horn near the apex of the lip and unlobed calli at its base.