Tree 3-24 m. Leaves membranous or thinly coriaceous, (elliptic-)oblong, 5—14(—16) by 1.5—5.5(—7.5) cm, base attenuate or rarely ± rounded, apex acute-acuminate, with ± blunt or acute tip; Inflorescences between the older leaves or below, of the Knema-type: a simple sessile scar-covered brachyblast up to 4 mm long, glabrescent; Fruits solitary, oblong, 4.5-6 by 2-2.5 cm, apex ± acute, often somewhat oblique, base narrowed into a 1-1.5 cm long pseudostalk, glabrous or glabrescent, hairs (grey-)brown, powdery, 0.1 mm;
Asia-Tropical, Papua Barat present, SW Papua New Guinea present, western half of New Guinea present
Malesia: mainly western half of New Guinea (Papua Barat and SW Papua New Guinea: Western Prov.).
Myristica tubiflora is a lowland species, characterized by leaves of a small size class, sessile inflorescences, elongate male flowers with long pedicels, with the (sub)persistent bracteole usually at some distance below the perianth (in most Myristica species the bracteole is apical) and elongate fruits. Sterile specimens and those with immature fruits may resemble M. lepidota subsp. montanoides, and some, now treated under M. tubiflora, may belong to that taxon or vice versa. This may partly account for the remarkable variation in leaf texture admitted for M. tubiflora: the majority of the specimens have subcoriaceous leaves, but some have brittle membranous leaves, with a more distinct venation, reminiscent of the leaves of M. lepidota subsp. montanoides. The latter subspecies, however, is distinguishable by its small flowers and fruits.