Acacias of Australia

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Vachellia ditricha (Pedley) Kodela

Common Name

Mamoose Tree




Occurs in the Gibb River–Mount Barnett Stns area of the Kimberley region, W.A., from Mainoru Stn S to Tanumbirina Stn, N.T., and Cape York Peninsula in the Mitchell R. area, Qld.


Shrub or tree to 5 m high, often spreading or straggly. Bark corky, furrowed. Branchlets with an indumentum of short (to 0.1 mm) and long (to 0.4 or 0.6 mm) ascending to erect hairs that also covers leaf axes, soon becoming corky, yellow-fissured and less hairy. Stipular spines 0.8–5 mm long, often inconspicuous. Leaves: petiole 0.1–0.5 (–1) cm long, with a raised gland at base of lowest pair of pinnae; rachis (1.2–) 4–10 (–14) cm long, eglandular; pinnae (5–) 20–45 (–50) pairs, (0.4–) 0.7–2 cm long; pinnules (9–) 20–30 pairs, mostly crowded, oblong to narrowly oblong or elliptic, mostly 0.4–1.8 mm long, 0.2–0.7 mm wide, obtuse, ±concolorous, ciliolate or ciliate, with raised midnerve beneath. Inflorescences simple, 1 or 2 in axils; peduncles 15–40 mm long, with involucel of bracts near middle; heads globular, 20–25-flowered, cream-coloured or yellow. Pods mostly ±narrowly oblong to cultrate or narrowly elliptic, slightly constricted between seeds, ±flat but slightly raised over seeds, mostly 3–8 cm long, 10–16 (–18) mm wide, coriaceous to ±woody, obliquely to longitudinally nerved, pubescent or puberulous, becoming almost glabrous.


Flowers recorded Jan.; fruits recorded Feb.–Aug.


Grows in open eucalypt woodland, grassland and seasonal Melaleuca swamp, in heavy clay alluvium, sandy loam or stony soils.


W.A.: 41 miles [66 km] SW of Gibb River HS, Kimberleys, J.R.Maconochie 1214 (BRI, CANB, DNA, NSW, PERTH). N.T.: near Flora R., S of Dorisvale Stn, R.A.Perry 2833 & M.Lazarides (BRI, CANB, DNA, K); Roper Hwy 32 km E of junction with Stuart Hwy, J.T.Waterhouse & B.S.Wannan (NSW, UNSW). Qld: Kowanyama – Topsy Creek, P.Black 657 (BRI); 16.6 km S of Rutland Plains on the track to Inkerman, J.R.Clarkson 9515 & V.J.Neldner (NSW, n.v. : BRI, CANB, MBA).


Based on molecular and other data Acacia sens. lat. is now considered as comprising a number of segregate genera, see J.T.Miller & D.S.Seigler, Austral. Syst. Bot. 25: 217-224 (2012) for overview. Many taxa in the former Acacia subg. Acacia are now referable to the genus Vachellia, including the one presented here.

Previously confused with V. bidwillii. The specimen J.R.Clarkson 3429 from ‘11.2 km E of Walsh R. crossing on the Wrotham Park-Dunbar road’ (K, NSW, n.v.: BRI, DNA, MEL, MO, PERTH, QRS) is unusual in having rachises to 16.5 cm long with up to 51 pairs of pinnae, the pinnules to 2 mm long, and in being a tree reaching 8 m high.

FOA Reference

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