Acacia leptocarpa A.Cunn. ex Benth.

Fabaceae

Bentham, G. (1842) London J. Bot. 1: 376. Type: Cape Flinders, Aug. 1820, Cunningham; holo: K; iso: BM.

Wattle

Usually grows into a small tree about 6-10 m tall but can flower and fruit as a shrub 2-5 m tall.

Leaves phyllodineous. Leaf blades falcate, about 12-21 x 1-2.5 cm, glabrous. A gland may be visible on the upper margin surface of the leaf blade-petiole junction but often not apparent. Veins longitudinal and parallel, three veins more prominent than the rest. Petiole somewhat swollen and longitudinally wrinkled. Stipules very small and inconspicuous.

Flowers yellow, pleasantly perfumed, spikes about 5-7 cm long, moderately dense, produced in pairs in the leaf axils. Flowers male or hermaphrodite. Calyx mainly glabrous, about 0.75-1 mm long. Corolla glabrous, about 1.9-2.4 mm long. Ovary densely pubescent.

Pods linear, curved or somewhat coiled, up to 12 x 0.3 cm. Seeds about 4 mm long, black, with the long axis parallel to that of the pod. Funicle orange, folded many times at the base of the seed forming an aril-like structure almost as long as the seed but not encircling the seed.

Cotyledons fleshy, oblong, about 6 x 2 mm. First leaf pinnate, second and third leaves bipinnate, subsequent leaves simple, linear and phyllodineous, venation longitudinal usually with 2 veins more prominent than the rest. Stipules +/- triangular, small and inconspicuous. At the tenth leaf stage: leaves phyllodineous, linear to narrowly elliptic, usually with two longitudinal veins more prominent than the rest. Leaf blade margins thickened and vein-like. A small gland may be visible on the upper side of the leaf blade-petiole junction. Stems angular (triangular). Seed germination time 7 to 11 days.

Occurs in WA, NT, CYP, NEQ, CEQ and southwards as far as south-eastern Queensland. Altitudinal range from near sea level to 700 m. Usually grows in open forest but occasionally found on the margins of rain forest, monsoon forest, vine thickets, beach forest and gallery forest. Also occurs in southern New Guinea.