Acacia assimilis S.Moore, J. Linn. Soc., Bot . 45: 172 (1920)
Dense shrub or tree 1–4 m high. Branchlets terete, glabrous. New shoots densely yellow appressed-pubescent. Phyllodes patent to ascending, filiform, straight to shallowly curved, terete, mostly 5–14 cm long, 0.8–1.3 mm diam., caudate-acuminate at apex with delicately curved, plumose or appressed-puberulous and glabrescent tip, green, glabrous (except tip), with numerous, closely parallel, fine nerves. Inflorescences simple, 2 per axil; peduncles mostly 6–11 mm long, appressed-puberulous or glabrous; heads globular to widely ellipsoid or obloid, 4–6 mm diam., mostly 30–70-flowered, golden or lemon yellow; bracteoles sometimes exserted in buds. Flowers mostly 5-merous; sepals free or shortly united basally. Pods linear, raised over and sometimes slightly constricted between seeds, straight, 3–8.5 cm long, 3–4 mm wide, glabrous or subglabrous. Seeds longitudinal, widely elliptic to ovate or oblong-elliptic, 2.5–3 mm long, dull, dark brown to black; aril subterminal.
A member of the ‘ A. fragilis group’ sometimes confused with A. aulacophylla or A. fragilis ; however, both relatives are distinguished by their 8-nerved phyllodes. Sometimes resembles A. triptycha .
Common from Mullewa SSE to Boxwood Hill and E to the Norseman- Scaddan area in south-western W.A., but the southern end of this range is occupied almost exclusively by subsp. atroviridis . The two subspecies are narrowly sympatric and a few collections suggest that hybridisation is possible, e.g. B.R.Maslin 2447 (PERTH).
Comprises two subspecies.
Phyllodes commonly light green, mostly 5–9.5 cm long; pulvinus slender, cylindrical, not flared at base; heads mostly 30–40-flowered
subsp. assimilis
Phyllodes dark green, mostly 8–14 cm long; pulvinus flared at base, often strongly compressed dorsi-ventrally; heads mostly 50–70-flowered
subsp. atroviridis
Acacia assimilis S.Moore subsp. assimilis
Phyllodes mostly 5–9.5 cm long, 0.8–1.3 mm diam., commonly light or bright green; pulvinus slender, cylindrical. Flower-heads mostly 30–40-flowered; bracteoles dark with at least apex well-exserted. Sepals more than 1/2 as long as the 1/2-2/3-united petals.
Common from Mullewa SSE to near L. Biddy (which is c. 45 km due NE of Lake Grace) and E to near Coolgardie and Norseman in south-western W.A. Grows in mallee heath and scrub, on wet, low-lying areas on hillocks and mountain slopes, in grey to yellow and brown sand or clay to sandy clay, often gravelly, to reddish granitic loam, overlying laterite or granite.
Type of accepted name
Bruce Rock, W.A., 1915, F.Stoward 116 ; lecto: BM, fide R.S.Cowan & B.R.Maslin, Nuytsia 10: 238 (1995); isolecto: BM, PERTH (Fragment ex BM); Cowcowing, W.A., F.Stoward 405 ; paralecto: BM, PERTH.
Illustration
M.Simmons, Acacias Australia 2: 113 (1988).
Representative collections
W.A.: 16 km E of Mullewa, R.J.Cumming 1934 (BRI, MEL, NSW, PERTH); Bendering, C.A.Gardner 9461 (CANB, G, NY, PERTH); 16 km W of Moorine Rock, B.R.Maslin 3201 (AD, NSW, PERTH); Stennet Rock, c. 48 km SSW of Norseman, K.Newbey 7679 .
Acacia assimilis subsp. atroviridis R.S.Cowan & Maslin, Nuytsia 10: 240 (1995)
Phyllodes mostly 8–14 cm long, 1–1.5 mm diam., dark green; pulvinus flared at base and wider than base of phyllode-blade. Flower-heads mostly 50–70-flowered; bracteoles neither dark coloured nor obviously exserted. Sepals half or less the length of the 2/3-3/4-united petals.
Common from near Dumbleyung S to near Boxwood Hill (c. 50 km due SSW of Jerramungup) and E to Kumarl- Scaddan area (Norseman- Esperance) in south-western W.A. Grows in yellow, orange-yellow or pale brown sand, sandy or gravelly loam or reddish granitic loam, often in association with granite, less commonly with laterite, in Casuarina scrub, Eucalyptus woodland, heathland or on open sandplains.
Type of accepted name
83.9 miles [135 km] from Albany on Borden- Pingrup road, W.A., 25 May 1973, A.M.Ashby 4724 ; holo: PERTH; iso: BRI, CANB, K, MEL, NSW, NY, PERTH.
Representative collections
W.A.: 141 km from Albany on Borden- Pingrup road, A.M.Ashby 4733 (B, BM, MEL, NY, PERTH, W); Kumarl, L.A.Horbury 102 (PERTH); 10 km W of Munglinup, B.R.Maslin 2556 (AD, K, PERTH); 6 km S of Mt Gibbs, K.Newbey 6384 (PERTH).
(RSC & 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.
