Tree 15-25 m. Leaves membranous or thinly chartaceous, (elliptic-)oblong(-lanceolate), (16-)24-35 by (5—)8—13.5 cm, base attenuate or acute, or narrowly rounded, apex acute-acuminate; Inflorescences among the leaves or just below, pedunculate, slender, almost glabrous, hairs scattered, 0.1 mm or less; Fruits 1 or 2 per infructescence, (elliptic-)oblong, 6-7 by 3-3.5 cm, rounded at both ends, with dense minute scurf of hairs 0.1 mm or less;
Asia-Tropical: Borneo present (Brunei present, Sarawak present), C & E Kalimantan present
Malesia: Borneo (Sarawak, Brunei, C & E Kalimantan).
2 Some deviating specimens from Sarawak and Sabah (see De Wilde 1. c.) may represent an as yet undescribed species. They key out to fruiting specimens besides M. iners and M. wyatt-smithii, but differ in general aspect. More material, including flowers, is needed to solve this problem. 1 Myristica extensa is similar to M. corticata and M. iners in leaf and inflorescence features, and to M. malaccensis in the club-shaped androecium. The species is also close to M. maxima, with widely branched paniculate inflorescences (and infructescences), stouter twigs, and larger leaves and male flowers. The leaves of M. maxima have more lateral nerves, a more distinct venation, a well-marked marginal nerve, and a greyish lower leaf surface with minute pale hairs (glabrescent) and distinct papillae. Its male flowers are larger, with a cylindrical, not club-shaped androecium and with some indumentum on the androphore. For differences with the other species mentioned above, see the keys. Fruiting specimens of M. extensa may resemble M. frugifera from the Philippines.