Acacia unifissilis Court, Nuytsia 2: 173; 174, fig. 3 & 176, fig. 4 (1978)
Compact shrub 0.15–0.7 m high. Branchlets rigid, puberulous, pruinose between the yellowish ribs. Stipules 1.5–4 mm long. Phyllodes continuous with branchlets and commonly shortly decurrent with them, linear to subulate or narrowly triangular, commonly recurved, pentagonal when very narrow, 1–3 cm long, 1–3 mm wide, pungent, rigid, green, glabrous, 5-nerved, the 2-nerved adaxial margin thick and nerve-like; midrib prominent; adaxial nerves sometimes submarginal so phyllodes appear 2-nerved per face. Inflorescences simple; heads sessile, globular or obloid, 8–20-flowered, light golden; bracteoles scarious, brown, fimbriolate, conspicuous in buds. Sepals united, deeply cleft adaxially, scarious, brown, fimbriolate; petals 5. Pods constricted between seeds, tightly coiled or twisted, 1–1.5 cm long (unexpanded), crustaceous, dark brown, glabrous. Seeds oblong-elliptic, 3–4 mm long, ridged peripherally; aril oblique.
Occurs from Kellerberrin S to Fitzgerald R. Natl Park and near Peak Charles Natl Park, south-western W.A. Grows in sand in heath, shrubland or Mallee communities.
The sessile heads, very unusual calyx and tightly coiled or twisted pods readily distinguish the species from taxa with similarly 5-nerved, pungent phyllodes, e.g. A. baxteri .
Type of accepted name
c. 9.6 km E of Rabbit Proof fence No. 1 (E of Muntadgin) towards Mt Hampton, W.A., 5 Aug. 1971, B.R.Maslin 1826 ; holo: PERTH.
Illustration
A.B.Court, loc. cit. ; M.Simmons, Acacias Australia 2: 43 & pl. 35 (1988).
Representative collections
W.A.: near Collgar, c. 10 km SSE of Merredin, A.M.Ashby 1803 (PERTH); 5 km N of Dunn Swamp, c. 80 km NE of Ravensthorpe, J.Taylor 737 et al . (PERTH); 0.8 km E of Newdegate towards Lake King, M.D.Tindale 3761 (A, AD, CANB, K, NSW, PERTH, US).
(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.
