Acacia oraria

Family

Mimosaceae

Botanical Name

Acacia oraria F.Muell.

Mueller, F.J.H. von (1879) Fragmenta Phytographiae Australiae 11: 66. Type: Syntypes: Rockingham-Bay, Dallachy (MEL, BM); Trinity-Ba y, Bailey (BRI).

Synonyms

Acacia oraria F.Muell. var. oraria, Bibliotheca Botanica 89(4): 819(1928), Type: ?. Acacia oraria var. typica Domin, Bibliotheca Botanica 89(4): 818(1928), Type: ?. Racosperma orarium (F.Muell.) Pedley, Botanical Journal of the Linnean Society 92: 249(1986), Type: ?. Acacia oraria var. amblyphylla Domin, Bibliotheca Botanica 89(4): 819(1928), Type: Mischwalder bei Cairns, auf sandigen Boden (DOMIN XII. 1909)..

Common name

Coastal Wattle; Wattle

Stem

Dead bark layered. Inner blaze very fibrous and stringy. Usually encountered as a small tree not exceeding 30 cm dbh. Often flowering and fruiting as a shrub.

Leaves

Leaves green or slightly glaucous, phyllodineous. Leaf blades about 5-8 x 1.5-3.5 cm. A small gland usually visible on the upper side of the leaf blade-petiole junction. Veins longitudinal, reticulate, generally three more prominent than the rest. Younger leaves and twigs have a slight grey or silvery sheen.

Flowers

Inflorescence usually a raceme of heads on peduncles about 4-7 mm long, heads about 30-40 flowered, covered with a white bloom when immature. Stalked nectaries with orange glands present at the base of each flower in the head. Calyx lobes fused to about the middle, oblong, obtuse, about 1-1.4 mm long. Corolla lobes rather narrow, fused to the middle, about 1.5-1.9 mm long, corolla about 1.5 times as long as the calyx. Stamens about 3-4 mm long. Ovary somewhat scurfy.

Fruit

Pods twisted or coiled, about 12 x 0.9-1.5 cm, scurfy. Seeds black, longitudinally oriented in the pod, about 4 x 3 mm. Funicle red or reddish, thickened, passing completely around the seed and then folded back on itself and thickened to form an aril-like structure beneath the seed.

Seedlings

Cotyledons obovate, about 4-5 x 3-4 mm. First leaf pinnate, second leaf bipinnate. By the third or fourth leaf stage: leaves bipinnate, petiole expanded and flattened. At the tenth leaf stage: leaves phyllodineous, elliptic or narrowly elliptic to slightly falcate, apex obtuse, base cuneate, glabrous, usually three main parallel veins run from the base to the apex; glands present at the apex of the leaf blade and also at the base almost on the petiole; stipules very small, visible only with a lens.

Distribution and Ecology

Occurs in CYP, NEQ and southwards as far as coastal central Queensland. Altitudinal range from sea level to 500 m. This species is usually encountered along beaches, but also found in open forest and as a rheophyte along creeks. It occasionally grows on the margins of monsoon forest and dry rain forest. Also occurs in Malesia (Timor).