Anisoptera laevis Ridley, Fl. Malay Penins. 1: 219 (1922)
Species name meaning for 'smooth' or 'without hairs'.
Bud and twig apex more or less densely pale brown to rust lepidote at first, becoming glabrous. Young twig c. 1.5
mm diameter, slender, terete, becoming rugose on drying; later smooth or minutely striated. Bud 3-7 by 2 mm,
compressed, hastate to ovate, acute. Stipule c. 10 by 3 mm, glabrous, hastate to linear. Leaves 7-11 by 3-4
cm, oblong to obovate, not bullate, epilose, rust-brown lepidote beneath; base obtuse or broadly
cuneate; acumen to 1 cm long; nerves 10-14 pairs, at 50-60 degrees angle, slender, curved; petiole 1.5-2 cm long. Panicle
to 12 cm long, terminal or axillary, lax, pendent, angular, slender, densely shortly pale brown puberulent
to glabrous; alternately doubly branched, branchlets short, bearing to 11 flowers; bracteoles to 2.5 mm
long, lanceolate, shortly pubescent. Bud to 2 mm long, subglobose. Calyx cupped at base; sepals subequal.
valvate. shortly grey-brown puberulent outside; 2 longer lobes slightly broader, obtuse. 3 shorter acute,
acuminate. Petals small, elliptic-oblong, glabrous, pale yellow. Stamens 15. subequal. as long as or
slightly longer than the style; filaments short, tapering to the anther; anther narrowly oblong, the inner cells
smaller than the outer; appendage to connective short, erect. Ovary encased in the base of the calyx, covered
by a discoid stylopodium. crowned by a filiform glabrous style: stigma 3-lobed. Fruit calyx glabrous at
maturity: tube 1.2-1.5 cm diameter, globose, to 8 mm diameter at the neck; 2 longer lobes to 15 by 1.5 cm,
spatulate, obtuse, c. 5 mm broad at base: 3 short lobes to 1.5 cm long. c. 3 mm broad at base, hastate to
linear, margin slightly revolute. Nut apex disc-like, shortly pubescent, flat; style remnant 5-8 mm long,
filiform, very slender. [from Flora Malesiana]
Inland lowland and hill forests to 900 m; widespread and often common.
Peninsular Malaysia and Borneo.
Malaysia: Mersawa durian, medang sawa, madang loh, pengiran durian (Sabah).