Bulbophyllum xanthoacron J.J.Sm., Bull. Dép. Agric. Indes Néerl. 45 (1911) 10
Type: Bogor cult. (Exp. Lorentz, Djibdja) s.n. (iso L [probable, s.n., no coll.])
Pseudobulbs close together, oblongoid-ovoid, longitudinally multigrooved, 1.5-2.1 by 0.63-0.9 cm. Leaf erect, petiolate, lanceolate, acute, thick coriaceous, 5.75-7.3 by 1.85-2.55 cm; petiole channelled-conduplicate, 0.8-1 cm long; base cuneate in the acuminate petiole; midrib above grooved; underneath obtuse, prominent. Inflorescences several on the rhizome, erect, 1-flowered; peduncle filiform, c. 1.9 cm long. Floral bract tightly tubular, keeled, subulate-acuminate, 0.35 cm long. Flower medium size, c. 1.5 cm diam. Sepals widely patent, slightly reflexed. Median sepal lanceolate, acute, concave, with convex base, 0.975 by 0.25 cm. Lateral sepals obliquely lanceolate, acute, concave, with convex base, c. 1 by 0.33 cm; nerves 5, dorsally prominent. Petals very small, broadly obliquely rhombic, convex, almost 0.1 by slightly over 0.1 cm; lower margin with a tooth. Lip porrect, large, in outline narrowly oblong; mobile attached to the column-foot with a thin membrane; basal 1/3rd part narrowed, claw-like concave,, in outline quadrangular-oblong, with thick base, underneath keels 2 ima basi gibberis reversed, obtuse, terminatis with, the margins erect, towards the base more raised, 0.17 by 0.15 cm; mid-lobe larger, in outline oblong-ovate, obtuse, strongly convex, above obtuse 5-ribbed, densely verrucose, margins strongly recurved, underneath near the apex almost touching, underneath hollow, 0.58 by 0.23 cm. Column curved, somewhat shiny, 0.23 cm long; clinandrium on either side of the anther partly bidenticulate; stelidia 3-dentate; column-foot very short, thick wart-shaped. Anther cucullate; connective strongly crested-thickened. Ovary 6-angular, between the ribs thinly grooved, 0.35 cm long; pedicel in the basal part articulate, c. 1.15 cm long. (After Smith, 1911 & 1913)
Colours: Pseudobulbs green. Leaf above somewhat shiny green, underneath pale opaque. Inflorescence dark purple. Median sepal shining, dark purple, apex golden yellow, margin yellowish. Lateral sepals shining, dark purple, apex and outer margins golden yellow, between the nerves suffused yellowish. Petals semitransparent, pale golden yellow. Lip orange-golden yellow. Column pale yellow, apex slightly striped red. Anther yellowish; connective pale green. Ovary green; pedicel pale green, in the basal part purple.
Habitat: Epiphyte in lowland forest.
Distribution: Malesia (New Guinea).
Distribution in New Guinea: Papua (Indonesia); see map 96-2000M.jpg.
Cultivation: Warm growing epiphyte.