Growth form Epiphyte or terrestrial, up to 40 cm high. Rhizome not seen. Roots not seen. Stem erect, sub-cylindrical, slightly compressed, producing new stems below the old flower head near the stem apex, 5-8-leaved, longest complete stem 11-12 cm long, 0.4-0.8 cm thick, completely covered by leaf sheaths, internodes 0.1-0.2 cm long. Leaf ligulate-lanceolate, thinly coriaceous, mid to dark shiny green above, paler and duller below; apex unequally 2-lobed, both lobes subacute; base narrowed; lamina 8.5-16 cm long, 1.3-1.7 cm wide; sheath tubular, glabrous, weakly striate, softly wrinkled in dry state, 1.5-2.1 cm long; apex toothed, with glabrous margin. Inflorescences terminal, multi-flowered, semi-globose, 2.5-3 cm wide, when young enveloped by a spathe. Spathe not seen; floral bracts oblanceolate-rhombic, thin, transparent, lacking a midvein, apex acute, 1.3 cm long, 0.5 cm wide. Flowers upright, glabrous. Median sepal narrowly elliptic, apex acute, 0.78 cm long, 0.29 cm wide. Lateral sepals forming broadly elliptic, unequally bilobed synsepal, 0.7 cm long, 0.5 cm wide, basal third with inner margins free and loosely enveloping spur, upper 2/3 connate, each obliquely oblong-elliptic, apex subacute, 0.7 cm long, 0.25 cm wide. Petal oblong-ligulate, apex acute, 0.72 cm long, 0.19-0.2 cm wide. Lip adnate to the base of the column for 2 mm long, ovate-elliptic, with five low lamellate veins, 0.25 cm long, 0.22 cm wide; epichile obtuse; hypochile spurred; spur saccate, apex obtuse, 0.5 mm long. Column semicylindrical, 0.275 cm long; clinandrium triangular; stelidia not seen. Anther not seen; rostellum not seen; stigma not seen; pollinia not seen; viscidium not seen. Ovary sub-cylindrical falcate, 0.95 cm long. Capsule not seen.
Distribution – Milne Bay, Papua New Guinea.
Habitat and Ecology - Epiphyte in montane forest along the Mayu river. Altitude 1775-2010 m. Flowering in July in the wild.
Notes - 1. Flowers white with an orange-yellow lip.
2. The epithet mayuensis refers to the location where the type specimen was found, the Mayu river.
3. Specimen observed: P.F. Stevens & J.F. Veldkamp LAE 55592 ; A. Kairo 45326 (AMES)