Tree, 4-30 m high. Leaves in whorls of (2 or) 3 or 4, coriaceous when dried; Inflorescence 1.5-18 cm long, terminal and axillary cymes, in whorls of 2-4, sometimes solitary, congested; Flowers fragrant, more than 30 on each inflorescence. Sepals ovate, unequal in size, apex acute, thick except along the margin, rough outside, smooth inside. Stamens inserted at 1 mm below the mouth, 0.7 of the length of the corolla tube; Fruit composed of 2 separate mericarps; Seeds 2 at either placenta.
Asia-Tropical: Borneo present; Maluku (Maluku present); New Guinea present; Philippines (Philippines present); Sulawesi (Sulawesi present), Solomon Islands present
Solomon Islands; in Malesia: Borneo, Philippines, Sulawesi, Moluccas, New Guinea.
This species is characterised by its short corolla tube and verrucose fruits (when dried), which make it most similar to O. oppositifolia. The shape and size of the leaf blades is very variable.
K. Schum. - in Engl. & Prantl, Nat. Pflanzenfam. 4. 1895: 156
Miq. - in Fl. Ned. Ind. 1857: 415
Markgr. - in Bot. Jahrb. Syst. 1927: 191
Merr. & L.M. Perry - in J. Arnold Arbor. 1943: 213
D.J. Middleton - in Tree Fl. Sabah & Sarawak. 2004: 43
Hendrian - in Blumea. 2004: 112
Markgr. - in Blumea. 1979: 246
H. St.John, Pacific Trop. Bot. Gard. 1973: 280
Pichon - in Bull. Mus. Hist. Nat. (Paris). 1947: 209
K. Schum. - in Bot. Jahrb. Syst. 1888: 214