Tree 6-30 m. Leaves membranous or thinly charta-ceous, oblong-lanceolate, 12-26 by 4-9.5 cm, base cuneate or (narrowly) rounded, apex acute-acuminate; Inflorescences between the lower leaves or below, of the Knema-type: a (sub)sessile (to 2 mm pedunculate) simple or forked, scar-covered, pubescent brachyblast 3(-5) mm long; Fruits solitary or 2 per infructescence, (sub)sessile, ovoid-oblong, 2.5-3.5 by 1.7-2.5 cm, base rounded or subtruncate;
Asia-Tropical, Bird's Head present, southern part of West and East New Guinea present
Malesia: southern part of West and East New Guinea (also Bird's Head).
1 In some specimens the thinly chartaceous leaves dry with a more or less undulate margin, giving the leaves sometimes a denticulate appearance; in reality the leaves never are denticulate. 2 The specimen von Romer 96 (southern West New Guinea) has the bark of the older twigs as in M. undulatifolia, but its very immature fruits have longer and more slender pedicels; possibly it could be referred to M.fatua or represents a separate, yet undescribed, new taxon.