Tree 7-25 m. Leaves membranous or (thinly) chartaceous, oblong or lanceolate, 6-16 by 2-3.5(-4) cm, base narrowly rounded or acute, apex subacute or blunt; Inflorescences between the leaves or below, pedunculate, early glabrescent, the lateral branches with sessile, slender, scar-covered brachyblasts, central axis short or reduced to one flower; Fruits not seen.
Asia-Tropical, Louisiade Archipelago present, Papua New Guinea present
Malesia: Papua New Guinea (Louisiade Archipelago). With two subspecies.
Closely allied to M. schleinitzii, the latter with a widespread distributional range; M. rosselensis differs in the more narrow leaves with acute base, and faint venation, and inflorescences with sessile lateral slender brachyblasts. Sinclair (1968) mentioned the glabrous androphore for M. rosselensis, but in M. schleinitzii the androphore may be ± glabrous as well. The leaves of M. rosselensis resemble those of M. clemensii.