Slender treelet, 1.5 m. Leaves membranous (or chartaceous), lanceolate, parallel-sided, 12-22 by 1.5-3 cm, base attenuate, apex long acute(-acuminate); Fruits (immature) solitary, oblong-fusiform, base narrowed (pseudostalk), apex acute, (4-)4.5 by 1.3 (-1.5) cm, hairs dense, rust-coloured, scurfy, 0.1-0.2 mm;
Asia-Tropical, Papua New Guinea present, Western Prov., Fly River, 528 mile Camp present
Malesia: Papua New Guinea (Western Prov., Fly River, 528 mile Camp); known only from the type.
Despite the numerous recent collections made in New Guinea, this species remains known only from the type specimen. The fragmentary infructescence shows that the female inflorescence has a short, 2 mm long peduncle, and therefore it is keyed out in the group of species with a pedunculate inflorescence; however, specimens with male inflorescences are needed to confirm this. Myristica ensifolia is readily recognizable since it is a dwarf tree with ensiform leaves which suggests it to be a rheophyte, but actually it was collected in ridge forest undergrowth. Microscopically the fine craterlike markings on the lower leaf surface are characteristic.