Ceratostylis rivularis Schltr., Repert. Spec. Nov. Regni Veg. Beih. 1 (1912) 250
Type: Schlechter 16595 (holo B, lost; iso AMES, BO, K)
Epiphytic, erect, caespitose, 13-16 cm high. Rhizome very short. Roots filiform, elongated, flexuose, shortly villose. Stems slender, terete, glabrous, 1-leaved, at the base covered with elliptic-lanceolate, acuminate, reticulate-nervose sheaths, 8-13 cm long, 1.75-2 mm across. Leaves short, subulate, acute, adaxially slightly sulcate, erect, often somewhat incurved, 2-3.5 cm long. Inflorescences few, arranged into a very small terminal capitulum, covered with apiculate, elliptic scales. Flowers erect-patent. Sepals oblong, narrowly obtuse, in basal half sparsely puberulous. Lateral sepals oblique, at the base along the anterior margin conspicuously extended and connate; mentum sac-like, oblong, obtuse, 2.5 mm long. Petals obliquely lanceolate, acute, glabrous, about as long as the sepals. Lip elliptic, narrower at the base, broadly obtuse, in front carnose-thickened, at the base with slightly incurved margins, 3.25 mm long, with two parallel, ciliolate lamellae arising above the base, decurrent in apical third of the lip. Column half as long as the lip, glabrous, arms large, oblong; foot as long as the column. Anther broadly conical, in front truncate, bilobulate, glabrous. Ovary shortly pedicellate, cylindrical, puberulous, about 0.4 cm long. (After Schlechter, 1911-1914).
Colours: Flower dirty reddish, lip apex golden yellow.
Habitat: Epiphyte in lowland rainforest. Altitude 300 m.
Flowering time in the wild: September.
Distribution: Malesia (New Guinea, endemic).
Distribution in New Guinea: Papua New Guinea. See map: 125-126M.JPG
Cultivation: Warm growing epiphyte, keep in light shade.