Tree 10-25 m. Leaves membranous, oblong(-lanceolate), 8-17 by 3.5-6 cm, base attenuate, apex acute-acuminate with the very tip usually ± blunt; Inflorescences glabrescent or with sparse hairs 0.1 mm, 2 or 3 times branched, many-flowered; Fruits not seen.
Asia-Tropical, East Sepik Prov present, Papua New Guinea present
Malesia: Papua New Guinea (East Sepik Prov.).
2 Markgraf (I.c.) described the fruits as globose, 13-15 cm diameter; pericarp 2 mm thick; seed globose, 1 cm diameter. The fruiting Ledermann-specimens, formerly in the Berlin herbarium, have been destroyed. 1 A noteworthy species because of its predominantly 3-lobed flowers. The only other species with 3- or 4-lobed flowers in New Guinea is the ± related H. olens. Horsfieldia sepikensis is reminiscent of Gymnacranthera paniculata var. zippeliana, which differs in the nature of the hairs (on leaf buds and flowers), in hairy perianths cleft to only about halfway, in a hairy ovary, and a different texture and colour of the leaves (whitish below). 3 The male flowers have been described by Markgraf (I.c., and probably erroneously) as cleft to about halfway.