Bulbophyllum centrosemiflorum J.J.Sm., Repert. Spec. Nov. Regni Veg. 11 (1912) 139
Type: Gjellerup 897 (holo BO)
Rhizome elongate, creeping, terete, 0.2 cm; sheaths tubular. Pseudobulbs c. 1.2-2.5 cm apart, obliquely erect, obliquely ovoid, strongly 4-5-ribbed, to c. 2.4 by 1.2 cm. Leaf elongate-linear, obtuse, conical-apiculate, somewhat fleshy, c. 13.75-27 by 0.7-1.2 cm; base narrowed into a petiole; above on either side convex; petiole which is at the base subterete or entirely sulcate. Inflorescences 1-flowered, from the nodes of the rhizome, 1-5 fascicled, erect; peduncle c. 1.2-1.4 cm long, in the basal part with a few small, overlapping, tubular sheaths. Floral bract tubular, obtuse, apiculate, 0.3 cm long. Flower medium size, c. 1.8 cm long. Median sepal large, at the base 0.3 cm adnate to the lateral sepals, subelliptic, largely convex, on either side papillose, finely ciliate, 5-nerved, reticulate-veined, c. 1.55 by 0.98 cm; base contracted, concave; margins above the base recurved; apex incurved, rounded, slightly apiculate. Lateral sepals decurrent on the column-foot, the adjoining margins to the apex connate, obliquely broadly elliptic, obtuse, 9-nerved, ciliate, almost 1.1 cm long 0.8 by 0.65 cm wide; mentum laterally compressed, rounded-angular; upper margin laxly uneven and wavy; inside in the posterior half except at the base long pilose, the rest on either side papillose. Petals very small, appressed to the column, obliquely suborbicular, 5-angular, rounded, concave, 3-nerved, outer nerves short, 0.23 cm long; base broad. Lip minute, curved, fleshy, subovate, obtuse, 0.23 by 0.2 cm; base truncate; upper side almost to the apex broadly channelled, with 2 longitudinal keels with prostrate hairs. Column short, dorsally convex, 0.23 cm long, with elongated, oblong, subacute, rather finely erose apex; clinandrium very small, concave; stelidia as long as the anther, bidentate. Anther cucullate, when seen from above quadrangular, almost 0.1 cm wide; base without ligament, delicately deeply notched; apex incurved, triangular, truncate. Pollinia oblong-semi-elliptic.; stigma longitudinal, oblong; column-foot making an almost straight angle with the ovary, strongly incurved, oblong, in lower part the margins high raised, strongly concave, near the middle the margins incurved, constricted, with truncate apex, when not flattened 0.38 cm long. Ovary pedicellate, sigmoid, 6-grooved, minutely furfuraceous-punctate, 0.5 cm long. (After Smith, 1916)
Colours: Flower yellowish white, all parts, especially the median sepal spotted brown-violet, the column uniformly yellow.
Habitat: Epiphyte in lower montane forest, often on the underside of horizontal branches; 400-900 m.
Flowering time in the wild: January, March, April, May, June, July, August, November, December.
Distribution: Malesia (New Guinea).
Distribution in New Guinea: Papua (Indonesia); Papua New Guinea; see map 96-308M.jpg.
Cultivation: Intermediate growing epiphyte, requires shaded position.