Horsfieldia laticostata (J.Sinclair) W.J.deWilde, Gard. Bull. Sing. 39 (1986)

Latin for 'broad veins'.

Horsfieldia brachiata var. laticostata J.Sinclair

Upper canopy tree up to 42 m tall and 56 cm dbh. Stem with red sap. Stipules absent. Leaves alternate, simple, penni-veined, glabrous. Flowers ca. 2 mm diameter, yellow-orange, placed in panicles. Fruits ca. 33 mm diameter, yellow-orange-red, glabrous, dehiscent capsules. Seeds with undivided orange aril.

Tree 12-35(-42) m. Twigs 3-8 mm diameter, early glabrescent, hairs grey-brown or rusty, 0.1-0.4 mm; bark coarsely striate, when older almost flaking; lenticels usually distinct. Leaves thinly to thickly coriaceous, (obovate-)oblong, (15-)20-33 by 6-12 cm, base attenuate, apex (short-)acute-acuminate; upper surface drying dull olivaceous-brown, glabrous, lower surface chocolate to rusty, contrasting with the upper surface, early glabrescent; dots absent; midrib raised above, towards the base +/- flat and conspicuously broad, 3-4(-5) mm wide at transition to petiole, sometimes with remnants of indumentum towards the base; nerves 11-20(-24) pairs, raised but towards the blade margin sunken, lines of interarching +/- distinct, sunken; venation lax, flat or sunken, distinct or not; petiole stout, 6-15 by 5-8 mm; leaf bud 15-23 by 3-5 mm, with dense grey-brown or rusty hairs 0.1-0.4 mm long. Inflorescences below the leaves, with sparse hairs 0.2-0.4 mm long; in male: stout, 4 or 5 times branched, many-flowered, 10-25 by 8-22 cm, main axis towards base 3-4 mm diameter, peduncle 0.5-3.5 cm long; in female: 3-7 cm long, 2 or 3 times branched, rather few-flowered; bracts elliptic, acute, 2-8 by 1-4 mm, with hairs 0.3 mm, +/- glabrescent, caducous; flowers (male) in clusters of up to 10, perianth 3-lobed, glabrous, pedicel glabrous except few hairs 0.1-0.2 mm long towards the base, distinctly articulated. Male flowers: pedicel 1-2 mm long, slender; buds broadly obovoid to subglobose, 1.3-1.5 mm diameter, apex broadly rounded, base rounded or sometimes +/- attenuate, glabrous, cleft c. 1/2, not collapsing on drying, lobes 0.2-0.3 mm, towards base of perianth 0.5 mm thick; androecium including androphore broadly obovoid in outline, 0.7 mm diameter, triangular in cross section; thecae 12, suberect, +/- acute, mutually largely free, 0.3(-0.4) mm long; androphore tapering, 0.3 (-0.4) mm long. Female flowers: pedicel 0.5-1 mm long; buds broadly ellipsoid-globose, 2.5 mm diameter, glabrous or with a few minute hairs 0.1 mm long, cleft c. 1/3; ovary broadly ovoid, 1.5 mm long, glabrous, stigma 0.1 mm long, shallowly 2(-4)- lobed. Fruits 1-4 per infructescence, ellipsoid, 2.8-4 by 2.2-2.5 cm, glabrous, with or without warts or lenticels; pericarp 4-5 mm thick; fruiting pedicel 2-4 mm long; perianth not persistent. [from Flora Malesiana]

In undisturbed keranga, peat-swamp and dipterocarp forests up to 800 m altitude. Usually on swampy, alluvial sites with poor clay to sandy soils, also on ultrabasic.


Local names
Borneo: Darah-darah, Kumpang, Piasau piasau.