A large lithophytic or terrestrial herb with several strap-shaped leaves. Leaves very coriaceous, ligulate, rounded at the apex, up to 60 cm long, 8–12 cm wide, glossy grass-green. Inflorescence suberect-spreading, up to 50–70 cm long, 3- to 5- (or more) flowered; peduncle purple, pubescent; bracts up to 6.5 x 2.2 cm, yellow heavily flushed with brown, densely red-brown pubescent. Flowers up to 6 cm across, 8-10 cm tall; pedicel and ovary white, densely reddish-brown pubescent on outer surface. Dorsal sepal 4-4.4 x 2.3–21.4 cm, ovate, acuminate, greenish yellow with three to five longitudinal maroon stripes in the basal two-thirds, purple-pubescent on outer surface. Synsepal similar to the dorsal sepal but smaller, 4–4.3 x 1.8–1.9 cm, green but lacking the maroon stripes. Petals lineartapering, arcuate-pendent, 7–10 x 1–1.2 cm, pale yellow spotted with red-brown in the basal half, with a few red-brown hairs at the base. Lip porrect, grooved on back surface, 5.4–6 cm long, 2–2.3 cm wide, very similar to that of P. stonei, flushed with pinkish brown on a paler background, glabrous on outer surface. Column short; staminode longitudinally elliptic-oblong, shallowly notched at apex, slightly concave, 17mm long, 14 mm wide, white with yellowish sides and bristly brown hairs on the side.