Acacia sclerosperma F.Muell., S. Sci. Rec . 2 (7): 150 (1882)
Dense, commonly rounded shrub or tree mostly to c. 4 m high and c. 4 m wide. Bark smooth and light grey to branchlet extremities. Branchlets glabrous or puberulous. Phyllodes usually narrowly linear or narrowly elliptic, terete to flat, 3–14 cm long, 1–17 mm wide, l:w = 2–130, thick, smooth, often wrinkled when dry, green to glaucous, glabrous, 4-nerved in all, 1-nerved per face when flat; glands 2 or 3, not prominent. Inflorescences 2–5-headed racemes; raceme axes 3–30 mm long, glabrous or puberulous; peduncles 4–15 mm long; heads globular, subdense, 15–25-flowered, golden; buds bright green. Flowers 5-merous; sepals united into a truncate calyx. Pods moniliform to submoniliform, 6–12 cm long, 1–2 cm wide, woody, golden brown, glabrous. Seeds longitudinal, spherical, 7–10 mm long, glossy, dark brown to black; aril red, hemispherical to depressed-clavate.
Occurs mainly in the Pilbara and Murchison districts, W.A.
Distinguished from most other members of the ‘ A. bivenosa group’ by its large, woody pods and large seeds. Two subspecies are recognised.
Phyllodes narrowly linear, 4.5–14 cm long, 1–4 mm wide, l:w = 24–130
subsp. sclerosperma
Phyllodes narrowly elliptic to narrowly oblong-elliptic, 3–6 cm long, 6–17mm wide, l:w = 2–6, glaucous
subsp. glaucescens
Acacia sclerosperma F.Muell. subsp. sclerosperma
Limestone Wattle
Branchlets usually glabrous. Phyllodes narrowly linear, terete to flat, often uncinate with the tip recurved, 4.5–14 cm long, 1- 4 mm wide, rarely 5 mm, l:w = 24–130, green to subglaucous. Racemes usually glabrous; heads 15–20 flowered.
Common in the Pilbara and Murchison regions S to near Mingenew and Mt Magnet, disjunct occurrences near L. Carnegie and Wongan Hills, W.A. Grows on coastal dunes, along creeks and flood plains, in sand, limestone, loam and clay, in scrub, shrubland and riparian woodland.
In the southern half of its range, plants of otherwise typical A. sclerosperma subsp. sclerosperma occur with puberulous branchlets and raceme axes. Elsewhere it forms putative hybrids with A. ampliceps , A. bivenosa , A. ligulata , and A. sclerosperma subsp. glaucescens ( fide A.R.Chapman & B.R.Maslin, Nuytsia 8: 251, 1992). Phyllodes often resemble those of A. scirpifolia .
Type of accepted name
Gascoyne R., W.A., 1881, O.Jones ; holo: MEL.
Synonymy
Acacia spodiosperma F.Muell., Proc. Linn. Soc. New South Wales ser. 2, 3: 164 (1888). Type: near Lake Austin, W.A., H.S.King ; holo: MEL.
Acacia leucosperma F.Muell. ex E.Pritz., Bot. Jahrb. Syst . 35: 302 (1904). Type: near Carnarvon, W.A., L.Diels 3653 ; n.v. Synonymy following J.H.Maiden, J. & Proc. Roy. Soc. New South Wales 51: 244 (1917).
Illustrations
M.Simmons, Acacias Australia 171 (1981); A.A.Mitchell & D.G.Wilcox, Arid Shrubland Pl. W. Australia 286- 287 (1988); A.R.Chapman & B.R.Maslin, Nuytsia 8: 271, fig. 5A (1992).
Representative collections
WA: 16 km SE of Windidda HS, R.J.Chinnock 843 (NSW, PERTH); 18.5 km NW of Wongan Hills towards Piawaning, R.Coveny 7858 & C.Slade (PERTH); S branch of Gascoyne R, 150 km N of Meekatharra, Great Northern Hwy, B.R.Maslin 4574 (CANB, MEL, PERTH); George R. crossing, North West Coastal Hwy between Roebourne and Whim Ck, B.R.Maslin 5753 (PERTH); Dorre Is., Shark Bay, R.D.Royce 5928 (PERTH).
Acacia sclerosperma subsp. glaucescens A.R.Chapm. & Maslin, Nuytsia 8: 274; 261, fig. 4D (1992)
Billy Blue
Branchlets puberulous, sometimes glabrous. Phyllodes narrowly elliptic to narrowly oblong-elliptic, infrequently narrowly oblong-lanceolate, 3–6 cm long, 6–17 mm wide, l:w = 2–6, acute with straight or incurved mucro, glaucous, new shoots green. Raceme axes normally puberulous; heads 20–25-flowered.
Occurs in near-coastal areas S of Carnarvon from Edaggee S to Woodleigh Stns, also inland near Gascoyne Junction. Grows in sand, sandy loam and stony, sometimes calcareous soil in open scrub, sometimes associated with chenopods or hummock grassland.
Resembles A. tysonii which differs especially in its shortly velvety phyllodes and narrower pods. Hybridises with A. sclerosperma subsp. sclerosperma around the 26 parallel on the North West Coastal Hwy where numerous intermediates occur.
Type of accepted name
37 km N of Overlander Roadhouse on North West Coastal Hwy to Carnarvon, W.A., 8 Aug. 1974, B.R.Maslin 3715A ; holo: PERTH; iso: CANB, K, PERTH.
Illustration
A.R.Chapman & B.R.Maslin, Nuytsia 8: 261, fig. 4D (1992)
Representative collections
W.A.: 8.5 km from beach on track W from North West Coastal Hwy, 46 km N of Overlander Roadhouse, A.R.Chapman 578 (BRI, NSW, PERTH) and 579 (MEL, PERTH); Pells Ra., Bidgemia Stn, A.Holm (PERTH); c. 71.5 km S of Carnarvon, North West Coastal Hwy, Jan. 1973, E.Parkin s.n. (PERTH).
(ARC & 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.
