Acacia signata F.Muell., Fragm . 4: 7 (1863)
Shrub or tree, usually wispy or straggly, 2–4 m high. Branchlets often arching or pendulous, pruinose. Phyllodes often pendulous, linear to linear-elliptic, straight to curved, 10–20 cm long, 4–10 mm wide, tapering to pulvinus, with acute to acuminate apex, coriaceous, grey-green to subglaucous, glabrous, with numerous, fine, subdistant, rarely anastomosing veins, the midrib the most evident, the yellow or yellowish marginal veins prominent; pulvinus 3–6 mm long. Inflorescences 1–4-headed racemes; raceme axes usually 2–8 mm long, rarely to 45 mm, pruinose, glabrous; peduncles 6–20 mm long, glabrous; spikes 12–23 mm long, 6–7.5 mm diam., golden. Flowers 5-merous; sepals united, puberulous. Pods linear, slightly raised over seeds, curved, c. 7 cm long and 5–6 mm wide, coriaceous, pruinose, glabrous. Seeds longitudinal, subdiscoid, compressed, 4–4.5 mm long, glossy, dark brown; pleurogram shortly U-shaped or nearly semicircular; funicle-aril short, thick.
Occurs from near Hamelin Pool S to Cockleshell Gully and E to near Wubin, W.A., and not common in this range. Grows in yellow sand and sandy loam on sandplains and flats in heath, scrub and shrubland.
Although the racemes are commonly 2–8 mm long, much longer ones, to 4.5 cm, are found occasionally (e.g., 12.8 km SW of Winchester, 1 Sept. 1974, C.Chapman , PERTH); examples of several racemes per axil are also found occasionally (e.g. from Witcherina, G.Phillips for A.M.Ashby 4838 , NY, PERTH). Data on habit are limited, but a whispy or straggly form from the Murchison R. area is often noted; there are other collections that omit such detail and a very few which note the plant as a compact shrub (e.g. 5 km S of Winchester, Sept. 1974, C.Chapman , PERTH, and from near the mouth of the Murchison R., J.S.Beard 2035 , PERTH).
Formerly confused with A. yorkrakinensis subsp. acrita which differs largely by its regularly densely branching habit, by its somewhat shorter pulvinus with red or brown phyllode margins and by its oblong-elliptic seeds with a conspicuous funicle-aril and elongate U-shaped pleurogram. There may also be a difference in phyllode colour, but the paucity of observations of this characteristic, as well as of habit and fruits, makes assessment of the taxa extremely difficult; future studies may suggest they be combined, each with infraspecific rank. Acacia yorkrakinensis extends SE from the Perenjori-Wubin area which is the southern end of the range of A. signata .
Type of accepted name
Murchison R., W.A., [A.F.]Oldfield ; holo: MEL; iso: K, NSW, PERTH (Fragment ex MEL).
Illustration
M.Simmons, Acacias Australia 2: 249 (1988).
Representative collections
W.A.: near Hamelin Pool, J.S.Beard 3028 (PERTH); 9.1 km on road from Kalbarri to Ajana, R.S. & R.A.Cowan A807 (CANB, K, NY, PERTH, US); 0.3 km N of Wubin on Wubin–Mullewa rd, N.Hoyle 332 (MEL, PERTH); 19.2 km N of Cockleshell Gully, W.A.Loneragan 67.032 (PERTH); 6.5 km N of Coorow, Geraldton Hwy, B.R.Maslin 4335 (PERTH).
(BRM & RSC)
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.
