Acacia collegialis Maslin
Acacia collegialis Maslin
Southern Rock Wattle
Fabaceae
Occurs from Coolgardie E to Karonie (c. 100 km E of Kalgoorlie) and S to the vicinity of Norseman, W.A.
Spreading shrub or tree 2.5–6 m tall. Bark dark grey, fibrous, longitudinally fissured. Branchlet ribs sometimes overlain by resin, glabrous or appressed-hairy at extremities. Phyllodes narrowly elliptic, acute to acuminate, 5–8.5 cm long, 4–7 mm wide, l:w = 8–21, falcately recurved, wide-spreading, finely multi-striate with central nerve slightly more pronounced than others, marginal nerve brown to red-brown and overlain by a ±thin to thick layer of light grey, opaque resin; gland basal. Inflorescences simple or rudimentary racemes to c. 1 mm long; peduncles (1–) 2–6 mm long, densely ±appressed puberulous when in flower; spikes obloid to short-cylindrical, 5–9 (–12) mm long, golden. Flowers 5 merous; sepals ±free. Pods linear to narrowly oblong, 4–8 cm long, 4–6 mm wide, ±thinly coriaceous-crustaceous, ±straight-edged, dark brown to dark red-brown (due to dense layer of glandular trichomes within a resin matrix), marginal nerve not or scarcely raised above face of valve. Seeds longitudinal in pods, mostly obloid, (3–) 4–6 mm long, with heart-shaped differentiated tissue at centre, aril creamy white.
Flowers Apr. –Aug.; mature pods Nov.–Dec.
Grows in shallow sandy clay-loam on rocky hills, commonly in Open Tall Shrubland or Open Low Woodland comprising scattered eucalypts, e.g. Eucalyptus griffithsii, E. longicornis.
A variant from Banded Ironstone Formation ranges about 150–200 km NE of Coolgardie probably belongs to this species, see B.R.Maslin, Nuytsia 24: 151 (2014) for discussion.
Related to A. quadrimarginea which has wider, ±woody pods with an obvious perpendicular marginal flange, larger seeds, commonly longer spikes and phyllodes that are often longer with a higher l: w ratio and which lack opaque resin on top of the marginal nerve.
Data derived from Flora of Australia Volumes 11A (2001), 11B (2001) and 12 (1998), products of ABRS, ©Commonwealth of Australia
B.R. Maslin and minor edits by P.G. Kodela
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