Acacia auriculiformis

Family

Mimosaceae

Botanical Name

Acacia auriculiformis A.Cunn. ex Benth.

Bentham, G. (1842) The London Journal of Botany 1: 377. Type: Goulburn and Sims Islands, N. Coast, Cunningham..

Synonyms

Racosperma auriculiforme (Benth.) Pedley, Botanical Journal of the Linnean Society 92: 247(1986), Type: ?.

Common name

Wattle, Northern Black; Wattle, Ear Pod; Wattle, Black; Northern Black Wattle; Ear Pod Wattle; Black Wattle

Stem

Dead bark layered. Living bark strong and fibrous.

Leaves

Leaves phyllodineous. Veins longitudinal, +/- parallel, anastomosing, about 3-5 veins somewhat thicker than the rest; marginal glands not obvious. Leaf blades about 10-16 x 1.5-2.5 cm. Petiole swollen, transversely wrinkled.

Flowers

Spikes yellow, up to 8 cm long, somewhat interrupted, flowers sparsely distributed in pairs in the upper axils. Calyx glabrous, about 0.7-1 mm long, shortly lobed. Corolla about 1.7-2 mm long, about 2-2.5 times as long as the calyx. Stamens about 3 mm long. Ovary densely pubescent.

Fruit

Pod flat, rather woody, glaucous, transversely veined, margin undulate, about 6.5 x 1.5 cm. Seeds shiny black, transversely oriented in the pod, about 5 x 3.5 mm. Funicle orange, encircling the seed.

Seedlings

Cotyledons oblong, elliptic or obovate, about 5-8 mm long. First leaf pinnate, second leaf bipinnate. By the third or fourth leaf stage: leaves bipinnate, petiole broadly flattened. At the tenth leaf stage: leaves phyllodineous, linear, glabrous, usually with two main veins running from the base to the apex; stipules very small, triangular, visible with a lens but falling early.

Distribution and Ecology

Occurs in WA (near the border with NT), NT, CYP and NEQ (as far south as Mt Molloy). Altitudinal range from near sea level to 500 m. Grows in rain forest but more frequently found in gallery forest or growing as a rheophyte along the creeks and rivers of Cape York Peninsula. Also occurs in New Guinea and Kai Island and perhaps other islands in eastern Malesia.