Medium sized terrestrial. Leaves 4?7, strap-like, to 17 cm long, to 4 cm wide, green. Flowers 7?10, to 7 cm wide, opening successively; summer. Dorsal sepal ovate, slightly larger than laterals, yellowish-green. Petals linear, narrower than dorsal sepal, spreading, margins wavy, slightly twisted, yellow, sometimes with brownish spots. Labellum deeply helmet-shaped, yellowish. Syn. P. chamberlainianum (Sander) Stein var. primulinum (M.W.Wood &P.Taylor) Braem.

Indonesia & Borneo.

P. parishii (Rchb. f.) Stein from China, Burma and Thailand is a medium sized epiphyte or epilith with glossy green leaves, 4-8 flowers that are mostly cream to green with reddish veins, spots or suffusions, dorsal sepal broader than the twisted petals, and a helmet-shaped labellum.

Source: Jeanes, J. (2005). Orchidaceae. In: Spencer, R.. Horticultural Flora of South-eastern Australia. Volume 5. Flowering plants. Monocotyledons. The identification of garden and cultivated plants. University of New South Wales Press.