Acacia thomsonii Maslin & M.McDonald, Nuytsia 10(3): 444 figs. 1 & 2 (1996)
Thomson’s Wattle
Often spindly shrub or tree 2–6 m high. New shoots encrusted with bronze or brownish resin at initiation, not viscid. Branchlets sericeous. Phyllodes patent to ascending, mostly slightly asymmetric, oblanceolate to narrowly oblong-elliptic, straight to shallowly falcate, 7.5–17 cm long, 1–2 cm wide, rounded-obtuse to subacute, green to grey-green, sparsely to moderately sericeous, multistriate with normally 3 nerves more evident that the rest, sparingly anastomosing. Inflorescences rudimentary 2-headed racemes with axes to 0.5 mm long; peduncles normally 3–7 mm long and sparsely sericeous; spikes 15–30 mm long, golden. Flowers 5-merous; sepals united to near apex. Legumes linear, straight to shallowly curved, mostly 4.5–8 cm long, 3–4 (–4.5) mm wide, firmly chartaceous to thinly coriaceous, glabrous to subglabrous. Seeds longitudinal, oblong, (3–) 3.5-4 (–5) mm long, glossy, dark brown to black; aril normally bright yellow.
Discontinuous in northern Australia from near Halls Creek, W.A., through N.T. to the Mount Isa region, Qld. Grows in usually skeletal, slightly acidic soil on dissected plateaux and rocky low hills (often along diffuse drainage lines) and stony or sandy plains.
A relatively short-lived species that regenerates prolifically from seed following fires and favourable rainfall. Usually produces seed precociously and in large quantities.
A relatively invariate species formerly confused with A. cowleana . Its closest relative, however, is A. colei which differs especially by its normally pale yellow-sericeous new shoots, wider, densely sericeous, darker coloured, more obviously reticulate phyllodes, longer spikes and strongly curved (rarely coiled) pods. The two species are sometimes sympatric. Putatively hybridises with A. gonoclada in N.T.
Currently under evaluation for multipurpose use in dry areas of sub-Saharan Africa; the potential of its seeds as a source of human food is also being assessed.
Type of accepted name
19 km due NE of Halls Creek township, W.A., 4 July 1993, B.R. Maslin 7300 ; holo: PERTH; iso: BRI, CANB, K, MEL, NY.
Representative collections
W.A.: Moola Bulla Stn, W of Halls Creek, C.E.Harwood 328-384 & M.McDonald (PERTH); 16 km SW of Halls Creek on Great N Hwy, B.R.Maslin 7157 (PERTH). N.T.: 2.4 km N of Dunmarra Roadhouse on Stuart Hwy, L.Thomson LXT1232A–J & K (BRI, DNA, PERTH). Qld: 35 km E of Camooweal, B.V.Gunn 2469 (PERTH).
(BRM)
The information presented here originally appeared on the WATTLE CD-ROM which was jointly published by the Australian Biological Resources Study, Canberra, and the Department of Parks and Wildlife, Perth; it was produced by CSIRO Publishing from where it is available for purchase. The WATTLE custodians are thanked for allowing us to post this information here.
