Small tree 4-5 m. Leaves cuneate-obovate, up to 40 by 16 cm, base ± attenuate, apex short-acuminate; Inflorescences on the older wood, to 25 by 10 cm, glabrescent, loosely flowered.
Asia-Tropical, NE Papua New Guinea present, Sepik Prov., 'Aprilfluss'; mountain slope near camp 18 present
Malesia: NE Papua New Guinea (Sepik Prov., 'Aprilfluss'; mountain slope near camp 18).
1 Known only from the type, now destroyed. Keyed out by Markgraf with crux-melitensis, both having clavate flowers. He mentions in the key that the perianth (not the androecium) is largely hollow, and in a note that the species is peculiar amongst the New Guinea Horsfieldias because of its large male flowers, which in other species are smaller and almost always broader than long, and that it is without close relatives. 2 The species is possibly related to or may be identical with H. ampliformis.