Plants up to 35 cm tall. Leaves 2–5, basal, rosulate, petiolate; petiole four to five cm long; blade up to nine cm long and two cm wide, narrowly lanceolate, acute to acuminate, pubescent. Pedunce pubescent, 1–3-sheathed, terminated by a densely many-flowered raceme. Flowers medium-sized, sepals glabrous. Floral bracts seven mm long, oblong- lanceolate to lanceolate, acute, glandular. Pedicellate ovary 18 mm long, densely pubescent. Dorsal sepal 13 mm long, three mm wide, narrowly lanceolate to linear-lanceolate, acute, veins 5, simple. Petals unguiculate, claw free part five mm long, filiform; lamina eight mm long, 2.5–3 mm wide, oblong-ligulate to ligulate-subpandurate, somewhat falcate, obtuse, with hook-like, slightly twisted lobe at truncate base adorned with oblong, canaliculate callus with two teeth on both sides. Lateral sepals connate together almost completely forming almost orbicular lamina 11 mm long and wide, slightly notched at the apex, deeply concave in the center, veins numerous, distal ones branching. Lip simple, almost sessile, four mm long, two mm wide, narrowly sagittate, canaliculate, acute at the apex, with prominent keel at the base becoming furculate in front. Gynostemium ca four mm long, long-stalked (Fig. 41). Ecology: Terrestrial or epiphytic in montane wet forest (Dodson & Vasquez, 1989). Flowering in February and November.
Notes: The unique character of this species is the petal adorned with an oblong, canaliculate callus with two teeth on each side. This element is not shown in the illustration of P. microglossa deposited in AMES. As all other characters of this taxon correspond to P. inaudita, we follow previous concepts (Schweinfurth, 1958; Dodson & Vasquez, 1989) that the two species are conspecific.
Incertae sedis: We are not completely sure whether the species characterized below actually occurs in Colombia. The only examined material is deposited in W and it was collected by Moritz, probably in this country. More material is required to confirm its occurrence in Colombia