红光树 hong guang shu

Trees to 25 m tall, 20-30 cm d.b.h.; bark grayish white, with longitudinal streaks, easily cracking; branches drooping; twigs with dense rusty scurfy pubescence, glabrescent. Petiole stout, 1.5-2.5 cm, pubescent, glabrous when old; leaf blade broadly lanceolate or oblong-lanceolate, rarely oblanceolate, (15-)30-55(-70) × (7-)8-15 cm, subleathery, glabrous on both surfaces, juvenile leaves hairy on abaxial surface, base cordate or rounded, apex acuminate or long acuminate, tip often obtuse; lateral veins 24-35 pairs, prominent on both surfaces. Male inflorescences stout, 1-1.5 cm, axillary or arising from axils of deciduous leaves. Male flowers large, bud obovoid or pyriform, 6-7 × 4-6 mm; pedicels 0.7-1 cm, with rusty pubescence; bracteoles near base of perianth; perianth lobes 3(or 4); staminal disk slightly concave; anthers 10-13, sessile. Female flowers without or with short pedicel; perianth ca. 6 × 4 mm; ovary ovate, rusty pubescent; stigma many lobulate, concave at center. Infructescences short, often with 1 or 2 fruits; fruiting pedicel 3-5 mm. Fruit ellipsoid or ovoid, 3.5-4.5 × 2.5-3 cm, with dense rusty dendritic hairs 1-3 mm; pericarp thick, 4-5 mm. Seeds ellipsoid or ovoid-ellipsoid, 2-2.6(-3) × 1.2-1.4 cm, rounded at both ends; testa thinly leathery, tawny when dry, with dense irregular slender grooves; aril red, slightly tearing at apex; chalaza nearly apical, concave, close to micropyle with distinct aperture. Fl. Nov-Feb, fr. Jul-Sep.

Moist dense forests, mountains, ravines; 500-1000 m. Yunnan (Jinping, Xishuangbanna, Yingjiang) [NE India (Sikkim), Laos, Nepal, Thailand].

This species, which was formerly confused with Knema furfuracea (J. D. Hooker & Thomson) Warburg (Myristica furfuracea J. D. Hooker & Thomson) from Malaysia (e.g., in FRPS 30(2): 178. 1979), is close to K. pierrei Warburg from S Vietnam.

The seeds contain ca. 24% fat, which is used in industry. The bark and heart wood secrete red latex. The timber of this species is rather heavy, with coarse fiber.