Tree 5-25 m. Leaves membranous, (oblong-)lanceolate, 20-40 by 4.5-12.5 cm, base attenuate, apex acute-acuminate; Inflorescences with sparse woolly stellate-dendroid hairs 0.2-0.4 mm; Fruits up to 10 per infructescence, ellipsoid, 1.7-2.2 by 1.2-1.7 cm, with rusty hairs 0.2 mm long, sometimes only remaining at the very base;
Asia-Tropical, Bagabag I present, Long I present, Madang Prov present, NE Papua New Guinea present, New Britain present, New Ireland present
Malesia: NE Papua New Guinea (Madang Prov.: Bagabag I., Long I.; New Britain; New Ireland).
Horsfieldia psilantha is related to and resembles H. laevigata, H. tuberculata, and H. whitmorei. Horsfieldia laevigata, a variable and widespread species as well, always has hairy perianths, though sometimes only scattered hairs are present; it usually has smaller leaves, and the fruits usually have many more and coarser lenticel-like tubercles. Horsfieldia tuberculata, variable and widespread, has similarly glabrous flowers, but the shape of the perianth is more tapered at the base, while in the present species it is more circular in lateral view, with the base not or but slightly tapered; H. tuberculata furthermore has glabrous fruits and ovaries. The leaves of H. whitmorei, a species from the Solomon Islands, sometimes have similar, rather regularly looping, submarginal veins, and similar fruits, but the male perianth is smaller, only 2 mm diameter or less, cleft to c. 9/10, with the base and pedicel hairy.