Horsfieldia reticulata Warb., Mon. Myrist. (1897)

Synonyms
Horsfieldia affinis W.J.deWilde
Myristica reticulata (Warb.) Boerl.

Diagnostics
Understorey tree up to 20 m tall and 29 cm dbh. Stem with red sap. Stipules absent. Leaves alternate, simple, penni-veined, venation very conspicuous, hairy below. Flowers ca. 2 mm diameter, green-yellow, placed in panicles. Fruits ca. 21 mm long, orange-pink-red, glabrous, dehiscent capsules. Seeds with undivided orange aril.

Description
Tree 7-20 m tall. Twigs 2.5-6 mm diameter, late glabrescent, hairs rusty, 0.5-1 mm long; bark striate, when old cracked but not flaking; lenticels absent or small and inconspicuous. Leaves membranous or chartaceous, rarely bullate, elliptic-oblong to lanceolate, 8-35 by 4-11 cm, base rounded to attenuate, apex acute-acuminate; upper surface drying (blackish) brown, glabrous, lower surface with (sub)persistent rather sparse (stellate or) dendroid hairs 0.5-1 mm long; dots absent; midrib +/- flat above, often late glabrescent; nerves 9-20 pairs, slender, (sunken or) raised, lines of interarching regular, distinct; venation lax, faint or distinct; petiole (7-)12-20 by 2-4 mm, pubescent; leaf bud 10-15 by 3-4 mm, with dense hairs 0.5-1 mm. Inflorescences with dense shaggy hairs 0.5-2 mm long; in male: many-tlowered, 4 or 5 times branched, 12-25 by 8-14 cm, peduncle 1.5-6 cm long; in female; fewer flowered than in males, 5-6 cm long; bracts triangular to oblong, acute, 3-9 mm long, densely pubescent, caducous; flowers in male in loose clusters of 2-6, glabrous, perianth 3- or 4- (or 5-)lobed, pedicel articulated. Male flowers: pedicel slender, 0.5-2 mm long; buds depressed-globose, 1.2-2 by 1.5-2(-2.5) mm, cleft 1/4-1/3, lobes 0.1-0.2 mm thick; androecium (depressed) globose, slightly impressed at the centre, 0.6-0.8 by 1-1.5 mm; thecae 20-24(-30), completely sessile, incurved towards the apex; column broad, with hollow up to +/- halfway; androphore slender or broad, 0.2-0.4 mm long, sometimes hidden by the anthers. Female flowers (from remnants under the fruits): buds 2.5-3 by 2-2.5 mm, cleft over halfway, lobes 3, probably with very weak indumentum. Fruits 4-7 per infructescence, ellipsoid. 2.3-2.7 by 1.7-2.1 cm, glabrous, with some paler wart-like tubercles; pericarp 1.5-2 mm thick; fruiting pedicel 3-4 mm long; perianth persistent. [from Flora Malesiana]

Ecology
In undisturbed to slightly disturbed (open) mixed dipterocarp forests up to 600 m altitude. Usually on hillsides and ridges, buta also common along rivers and streams. On clay to sandy soils.

Uses
Fruits are edible.

Distribution
Borneo.

Local names
Borneo: Koompang batu, Kupang, Kumpang balau, Mandarahan, Rumpa'n.