Horsfieldia macrothyrsa Warb.

Tree 4-15 m. Twigs (2-)2.5-6 mm diameter, (blackish) brown, early glabrescent, hairs (grey-)brown, 0.1 mm long; bark finely striate, not flaking; lenticels usually distinct. Leaves membranous, (elliptic-)oblong, 12-28 by 4-12 cm, base attenuate, apex acute-acuminate; upper surface drying olivaceous to brown; lower surface early glabrescent; dots (no dashes) present (lens!); midrib ± flat above; nerves 9-17 pairs, thin, flat or ± raised above (see note 2), lines of interarching indistinct; venation lax, indistinct on both surfaces; petiole 12-20 by 2-4 mm; leaf bud 10-15 by 1.5-3 mm, with dense (grey-)brown hairs 0.1 mm. Inflorescences with sparse hairs 0.1 mm or less; in male: about 3 times branched, ± few-flowered, 7-20 by 5-12 cm, peduncle 0.5-4.5 cm long; in female (according to infructescences): about twice branched, 3-6 cm long; bracts elliptic-oblong, 2-4 mm long, short-pubescent, caducous; flowers in male in loose clusters of 2-4, in female 1-3 together, glabrous; the perianth 3-(or 4-) lobed, pedicel not or but faintly articulated. Male flowers: pedicel 1-2 mm long, usually slender, clearly marked-off from the perianth; buds globose to (depressed-)broadly obovoid, 3-4.3 by 3-4 mm, cleft c. 1/2, lobes 0.2-0.4 mm thick; androecium (depressed) globose or depressed broadly obovoid, 1.8-2.2 by 1.8-2.5 mm, in cross section circular to bluntly 3-or 4-angled (Plate 3: 91); thecae 30-44, completely sessile, free apices up to 0.1 mm long, towards the apex somewhat curved into the rather broad, 0.4-1.2 mm deep, apical cavity of the column; androphore narrow, 0.1-0.4 mm long, hidden by the anthers. Female flowers not seen. Fruits 2-6 per infructescence, glabrous, ovoid-ellipsoid, 2.2-2.5 by 1.6-1.8 cm, with or without a few small lenticel-like tubercles; pericarp 1.5-3 mm thick; fruiting pedicel 2-5(-7) mm long; the perianth not persistent.

It is a tropical plant.