van Nouhuys s.n. (October-November 1909) (syntype, BO)
Growth form Epiphyte, slender. Rhizome not seen. Roots filiform, long, flexible, glabrous. Stem somewhat compressed, proliferously leafed, completely covered by leaf sheaths, internodes 1.1-1.3 cm long. Leaf linear-lanceolate, towards the apex gradually narrowed, above on either side of the longitudinal groove convex, sparsely blackish punctate; base shortly cuneate-contracted; apex strongly unequal 2-lobed, shorter triangular, acute, longer truncate; lamina 4-4.7 cm long, 0.44-0.66 cm wide; sheath tubular, warty, margin whitish lacerate-fimbriate; apex toothed, with bristled margin. Inflorescences terminal, one-flowered, when young enveloped by a spathe. Spathe oblong, warty, membranous, clasping both floral bracts and the spur, convolute, 1.85-2.15 cm long, 0.9-1 cm wide; floral bracts not seen. Flowers upright, sepals bent backwards, glabrous. Median sepal linear, basal part slightly dilated, convex, 7-9-nerved, apex long acute, conical-apiculate, 3.2 cm long, 0.5 cm wide. Lateral sepals at base obliquely dilated shortly connate, clasping the spur, strongly convex, 7-8-nerved, apex not seen, 0.46 cm long. 0.5 cm wide. Petal linear, strongly convex, 7-nerved, apex obtuse, 2.7 cm long, 0.47 cm wide. Lip adnate to the column, rhombic, concave, carnose, 0.67 cm long, 0.6 cm wide; epichile obtuse, recurved, thickened margin; hypochile spurred; spur appressed to the ovary, dorsally compressed, linear, apex obtuse, 2.4 cm long, 0.14 -0.18 cm wide. Column 0.48 cm long, basal half adnate to the lip; clinandrium large, somewhat wavy-crenate; stelidia not seen. Anther not seen; rostellum semiorbicular, bidentate; stigma transverse, lower margin elongated recurved semiorbicular, equaling the rostellum; pollinia not seen; viscidium not seen. Ovary elongated, gradually thickened towards apex, 6-grooved, 2.4 cm long. Capsule not seen.
Habitat and Ecology - Epiphyte in upper montane forest in exposed positions. Altitude 2577-3260 m. Flowering in March, July, October and December in the wild.
2. The epithet grandiflora refers to the relatively large size of the flowers (grandis meanslarge in Latin and –floris meansflower)
3. Specimen observed: von Romer 1292; Lam 3260.