Bulbophyllum riparium J.J.Sm., Nova Guinea 14 (1929) 462, pl. 75, fig. 109
Type: Bogor cult. (Exp. Lorentz, Djibdja 41) s.n. (holo L [probable, s.n., no coll.])
Rhizome elongated, pendulous, branched, geniculate, terete, ribbed, brownish, c. 60 by 0.13 cm diam.; entirely covered with prominently veined brown furfuraceous tubular sheaths. Roots appressed. Pseudobulbs c. 2.5-5 cm apart, very small, appressed to the rhizome, subterete, ribbed-angular; underneath flattened, green, 0.33-0.45 by 0.13 cm; 1-leaved. Leaf petiolate, oblong; apex recurved, rounded, base cuneate, above broadly channelled with a longitudinal groove; towards margins convex; underneath with slightly prominent midvein, convex, rigidly fleshy, shining green, impressed punctate, c. 2.75-4. by 1.1-1.5 cm; petiole thin, above grooved, 0.3-0.5 cm long. Inflorescences from the nodes of the rhizome, many, 1-3 fascicled, very short, 1-flowered; peduncle inconspicuous and basal part covered by rhizomes sheaths, white, 0.15-0.25 cm long; with a few small delicate acute somewhat shiny sheaths. Floral bract clasping the ovary and surpassing it in length; base tubular, triangular, acute, concave, semitransparent, white, 0.13 cm long. Flower patent, somewhat open, 0.67 cm long or somewhat larger; sepals parallel. Median sepal with a triangular concave 0.2 by 0.12 cm basal part, top part contracted, long subulate, in total 0.67 cm long. Lateral sepals proximally forming a short broadly conical obtuse mentum with the column-foot; proximally obliquely triangular concave 0.17 cm by 0.13 cm, top part contracted, long subulate, 0.7 cm long. Petals very small, porrect, parallel, subelliptic, obtuse, hardly concave, white, semitransparent, 0.13 by 0.07 cm. Lip mobile, proximally with the margins erect, channelled-concave in between, distally convex with recurved margins, when flattened ovate, gradually narrowed to the obtuse apex, 0.15 by 0.08 cm. Column short, white, 0.06 cm long, filament triangular; stelidia somewhat long, obliquely oblong-triangular, slightly falcate, acute. Anther cucullate, suborbicular; stigma rather large; column-foot making an obtuse angle with the ovary, oblong, obtuse, 0.06 cm long. Ovary obconical, 6-grooved, 0.05-0.06 cm long. (After Smith, 1929)
Colours: Sepals yellowish, base white. Petals white Lip lemon-yellow, apex ochrish.
Habitat: Epiphyte in lowland forest; 1600-2000 m.
Distribution: Malesia (New Guinea).
Distribution in New Guinea: Papua (Indonesia); Papua New Guinea; see map 96-1592M.jpg.
Cultivation: Warm growing epiphyte.