Acacias of Australia

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Acacia alleniana Maiden




Occurs from near Darwin to Arnhem Land and islands of the Gulf of Carpentaria (Bickerton Is. and Groote Eylandt), N.T., SE to Westmoreland Stn in extreme north-western Qld.


Spindly open shrub or tree to 5 m high; branches sometimes pendulous. Branchlets slender, with scattered lenticels, dark red-brown, glabrous. Phyllodes filiform, terete to quadrangular, 12–24 cm long, 0.5–0.8 mm wide, acute, not rigid, longitudinally sulcate when dry, puncticulate, glabrous; nerves not evident; gland obscure, 3–15 mm above pulvinus; pulvinus prominent, 1–2 mm long. Inflorescences simple; peduncles 2–6 per axil, 6–13 mm long, slender, glabrous; basal bract persistent; heads globular, c. 35-flowered, yellow; bracteoles exserted in buds. Flowers mostly 5-merous; sepals free, linear-spathulate. Pods linear, prominently raised over seeds alternately on each side, to 15 cm long, 3.5–5 mm wide, very thinly coriaceous, glabrous. Seeds longitudinal, oblong to elliptic, 4–5.5 mm long, 2–2.5 mm wide, turgid, ridged at periphery, dull, mid-brown, dark coloured bordering pleurogram; funicle filiform, scarcely arillate.


Grows in skeletal soil in hilly sandstone country.


N.T.: 21 km N of Jim Jim Falls, Kakadu Natl Park, M.Lazarides 9077 (DNA); 29 km NE of new Tanumbirini HS, N.McHenry 9 (AD, PERTH). Qld: Westmoreland Stn, C.H.Gittins 828 (BRI).


Closely allied to A. jasperensis. Also related to A. juncifolia which differs by its broader, non-puncticulate, obscurely 4-nerved phyllodes (observe at x10 mag.), fewer heads per axil, non-exserted bracteoles in young buds and its mottled seeds.

FOA Reference

Data derived from Flora of Australia Volumes 11A (2001), 11B (2001) and 12 (1998), products of ABRS, ©Commonwealth of Australia