Terrestrial or lithophytic herbs, clinging tightly to rocky stream banks, forming mats with mosses and grasses. Rhizomes brown, to 2 cm long, plants congested. Leaves linear, sedge- like, 30-55 cm long, 0.6-1.2 cm wide, up to 3.0 cm wide at base, wiry, arcuate, strongly keeled, glabrous, dark green, lighter green below; margins revolute; apex acute, finely bilobed or trilobed, oblique. Inflorescence a spicate raceme or panicle to 55 cm high, but often shorter, erect, 3-6 flowered , when branching to 10-flowered; bracts sheathing axils of panicle. Peduncle dark reddish-brown, tomentose; hairs uniseriate, multicellular , glandular, basal cell often swollen. Floral bracts ovate to triangular-lanceolate, 2.5- 5.0 cm long, 0.9-1.8 cm wide, greenish-yellow, often tinged with dark red; margins hyaline, overlapping just above the base; apex acuminate, minutely bifid. Sterile lower bracts 1-3, lanceolate, 7-25 cm long, 0.8-1.4 cm wide, lowest 8-12 cm from plant base; margins thin; apex acute, minutely bifid. Flowers yellow-green suffused with brownish-orange, nerves reddish-brown; outer surfaces mostly glabrous; inner surfaces mostly puberulent to tomentose; margins white. Dorsal sepal elliptic, 2.5-4.0 cm long, 0.8-1.2 cm wide, white with 12-15 red-brown and green nerves; margins to 1 mm wide, slightly undulate; apex acute, minutely hooded. Synsepal ovate, 2.0-3.0 cm long, 1.8-2.5 cm wide, equal to or shorter than labellum, 18-22 nerved; margins white; apex obtuse, minutely hooded. Labellum oval, 2.5-3.2 cm long, 1.5-1.9 cm wide at widest point, brownish-orange outside, whitish-yellow with brown-red spots inside; labellar opening widely ovate, slightly flared; apical labellum rim entire, glabrous, edged with a thin brown line; apical labellum lining to 0.7 cm wide; lateral labellum rim lacking spurs, edged with multicellular hairs; lateral labellum lining to 0.7 cm wide, area of margin fusion to 0.8 cm long; claw face beige with brown-red spots that grade in size and clarity from small and distinct above to larger and poorly defined below; claw interior pilose, spotted . Petals linear-lanceolate, 5.0-8.3 cm long , 0.4-0.7 cm wide, held at 25-35º angle from labellum, twisting 1-2 turns, inner-surface densely short puberulent, more so at apex; hairs reddish-gold, multicellular, glandular; basal hairs to 2 mm long; margins white, sparsely ciliate, somewhat undulate; apex acute, densely covered in glandular hairs. Staminode transversely rhombic, widest at the center, 0.4-0.5 cm long, 0.6-0.8 cm wide, light yellow to green, glabrous; apex acute; basal margins sparsely to densely edged with short, dark-purple multicellular hairs. Column 0.3 cm long, yellow with sparse, fine red hairs. Pollinarium 2 mm long . Stigmatic area 0.4 cm wide . Ovary , including pedicel, 4.8-5.5 cm long, glabrous to sparsely puberulent; hairs uniseriate, 1-4 celled, glandular, often deciduous at maturity. Capsule dark brown to brown with maroon splotches, glabrous to rough-glaucous, floral end strongly curved. Chromosome number 2n=21 and 22 (Karasawa, 1980 [Karasawa's P. pearcei types 2 and 3]).