2n = [52]

2n = c. 50, 50–54

2n = [50]

Tuberous terrestrial herb growing in loose groups. Leaves 8-14, ovate-elliptical to elliptical-Ianceolate, 1-2.4 cm × 3-7 mm, dark green, some with a few whitish variegations, the lower ones petiolate, arranged in a tight rosette, distal ones sessile and closely stem-embracing, apex acuminate; petioles 1-8 mm × 1-1.5 mm, narrowly winged. Flowering plants 8-14 cm tall. Scape slender, smooth. Flower solitary (rarely 2), 1.8-2.5 cm long, translucent green with darker green longitudinal and transverse veins, brownish towards the apex of the galea and lateral sepals; galea erect in proximal two-thirds then obliquely erect or curved forwards nearly at right angles. Dorsal sepal 18-24 mm × 12-13 mm, inflated at the base and tapered to the apex, with a short apical point 0.5-1.5 mm long. Lateral sepals deflexed; conjoined part 7-9 mm × 3-4 mm, narrowed to c. 2 mm across at the base, with a thickened, dark green central pad, the margins incurved; free points 7-11 mm long, linear, thickened, usually brown, parallel or slightly divergent, apex subacute. Petals strongly asymmetric, falcate, 15-20 mm × 1.5-2 mm, dark green, narrowed in the distal half to an attenuated, long-acuminate apex; flange c. 0.5 mm across, obscure. Labellum porrect, curved, filiform, densely beset with yellow hairs, with an apical knob; lamina linear-filiform, 13-15 mm × c. 0.5 mm, widened into a narrowly ovate, slightly wrinkled base c. 1.5 mm across, then suddenly tapered into a short beak, tapered slightly from the base to the apex; trichomes 2-4 mm long, yellow, irregularly moniliform, a series of short, whitish erect hairs on the basal swelling; apical knob irregular, c. 2 mm × 1.3 mm, dark brown. Column 12-14 mm long, porrect from the end of the ovary. Column wings 4-5 mm long; basal lobe 1.5 mm × 1 mm, at an angle of about 20°, inner margins incurved, sparsely adorned with white cilia, apex obtuse; mid-section c. 3 mm long, transparent; apical lobe 3-4 mm, linear. Stigma c. 6-7 mm × 2.5 mm, elliptical, raised. Anther c. 1.8 mm long, shortly rostrate. Pollinia c. 2 mm long, oblong, yellow, mealy. Capsule obovoid, 1.2-1.6 cm × 6-8 mm, asymmetrical.

P. plumosae L.Cady aflinis statura humiliore, foliis et floribus parvioribus, floribus autogamatis, labello plumosiore dense et apice galeae breviore non-attenuata differt.