Growth form Epiphyte, up to 80 cm high. Rhizome strong, rooting, similar as stem. Roots filiform, long, flexible, glabrous. Stem strong, erect to ascending, rigid, feathered-branches, cylindrical, proliferously leafed, completely covered by leaf sheaths, 0.33 cm in diameter, internodes 2-3 cm long in main stem, on branches 0.3-0.4 cm long. Leaf linear-lanceolate, channeled above, convex below, carnose; apex oblique, unequally 2-lobed, shorter narrowed obtuse-acute, longer oblong-obtuse to sub-truncate; base shortly contracted, appressed against the branches; lamina 1-1.5 cm long, 0.15-0.3 cm wide, petiole 0.1-0.05 cm long; sheath tubular, densely warty, longer than internodes; apex toothed, with bristled margin, bristles 0.05-0.06. Inflorescences terminal, sessile, nutant, one-flowered, when young enveloped by a spathe. Spathe cucullate-clasping, base tubular, obtuse, apiculate, punctate, 0.66 cm long; floral bracts thin, transparent, tubular, obtuse, 0.6 cm long, sometimes higher than spathe. Flowers upright, glabrous, 0.775 cm long, carnose, sepals and petals reflexed. Median sepal lanceolate, base narrowed towards apex, apex recurved, convex, 0.75 cm long, 0.2 cm wide. Lateral sepals oblique-lanceolate, subfalcate, higher part slightly contracted, convex, 3-nerved, 0.7 cm long, up to mentum 0.325 cm wide, above mentum 0.2 cm wide; apex obtuse, apiculate; base shortly connate in the anterior margin; mentum oblique, oblong, obtuse, concave, enclosed the spur, dilated 0.16 cm long. Petal narrowed lanceolate, convex, 3-nerved, apex obtuse, 0.67 cm long, 0.15 cm wide. Lip adnate to the column oblique-cupuliform, surpassed the column, up to the apex of ovary 0.23 cm long, with spur 0.64 cm long, convex below, when flattened quinquingular, 0.27 cm long, 0.3 cm wide; epichile 3-lobed, with transverse-thickened keel in lower part, lateral lobe erect subangular-rounded, terminal lobe slightly short with dark triangle; hypochile spurred; spur shorter than ovary, dorsally flattened, obtuse, straight, 0.4 cm long. Column base adnate to the lip, convex, 0.15 cm long, with colum foot; clinandrium conspicuous, dorsal margin slightly obtuse-angled, recurved, irregularly crenulate; stelidia not seen. Anther not seen; rostellum semi-orbicular, rounded-cutout; stigma semi-orbicular, inferior margin rounded, recurved; pollinia not seen; viscidium absent. Ovary cylindrical, glabrous, with pedicel 0.6 cm long. Capsule not seen.
Distribution – Indonesia.
Habitat and Ecology - Epiphyte in upper montane forest of Mt. Murkele. Altitude 1900-2500 m. Flowering in July in the wild.
Notes - 1. Flowers light green, with white lip.
2. The epithet plumosa refers to the featherlike branches of the species (plumose means feathered or winged in Latin).
3. Specimen observed: L. Rutten 1497.