Semecarpus aruensis Engl.

Small tree, sometimes a shrub, 3-14 m high. Bark light brown, fissured. Leaves spaced, spiral, chartaceous or subcoriaceous, obovate to oblanceolate, sometimes narrow-oblanceolate, rarely elliptic, (10-)15-28(-34½) by (3½-)5-8½ (-15) cm; upper surface glabrous but sometimes pubescent on midrib, nerves, and veins; lower surface pubescent, papillae distinct, covering the surface except the midrib and nerves; base cuneate to attenuate, sometimes rounded; apex short-acuminate or slightly rostrate; nerves (10-)17-25 pairs, prominent beneath, slightly immersed or flat, sometimes faint above; veins reticulate, some oblique or perpendicular to the nerves, slightly elevated below, distinct sometimes faint above; petiole l-2(-3½) cm. Panicles terminal and/or axillary, rarely raceme-like, 3½-27(-38) cm long; lateral branches obliquely ascending, up to 4(-10) cm; bracts ovate or triangular, lanceolate, or linear, 1½-4½ mm long; pedicels 0 or very short in ♂ (2 mm in ♀). Flower-buds subglobose. Flowers white. Calyx lobes triangular, ½-1 mm long. Petals valvate, elliptic, or ovate-oblong, 2-3 by 1-1½ mm in ♂ (c. 4½ by 2 mm in ♀), sericeous outside, with 6-10 longitudinal veins. Stamens 1½-4 mm; anthers broad-ovoid, c. ⅔ mm long. Imperfect or sterile stamens c. 2 mm. Disk round, flat, c. 1 mm Ø in ♂ (c. 2½ mm Ø in ♀), densely pubescent above. Ovary subglobose, c. 2 mm Ø, velutinous; style 1¾ mm long. Drupe broad-ovoid or ovoid, 2-3¼ by 1½-2 cm, velutinous; apex short-acuminate; hypocarp obconical or pulvinate especially when young, 1-1½ by 1-1½ cm, sometimes deformed and discoid up to 2 cm Ø.

Lowland forest, sometimes on riverbanks, up to 175 m, rarely up to 300 m. Fl. Febr.-Oct.; fr. Febr., March, Aug.-Nov.The fruit has a pocket-or pit-like insect-shelter formed on the outer surface (see p. 399 and Fig. 48c). So far, I found such an insect-shelter only on fruits of the present species.