Acacia sclerosperma F.Muell. subsp. sclerosperma
WATTLE
Acacias of Australia
Common Name
Limestone Wattle
Family
Fabaceae
Distribution
Common in the Pilbara and Murchison regions S to near Mingenew and Mt Magnet, with disjunct occurrences near Lake Carnegie and Wongan Hills, W.A.
Description
Branchlets usually glabrous. Phyllodes narrowly linear, terete to flat, often uncinate with tip recurved, (5–) 6–14 (-17) cm long, (0.5-) 1-4 mm wide, rarely 5 mm, l:w = (8–) 24–130, green to subglaucous. Raceme axes usually glabrous; heads 15–20 flowered.
Phenology
Flowers May.-Aug. with main flush seemingly in June.-July.
Habitat
Grows on coastal dunes, along creeks and flood plains, in sand, limestone, loam and clay, in scrub, shrubland and riparian woodland.
Specimens
W.A.: 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).
Notes
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 (see A. ampliceps × sclerosperma subsp. sclerosperma), A. bivenosa (see A. bivenosa × sclerosperma subsp. sclerosperma), 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.
Phyllodes vary from terete to flat and are normally thick-textured. Two variants with thin-textured phyllodes and with a propensity to root sucker (a character unknown for mainland plants of the subspecies) occur on Thevenard and Airlie Islands off Onslow (typical subsp. sclerosperma also occurs on these islands). Additionally, on these islands the entities can normally be recognized by their phyllodes: (5–) 7–9 cm long, 1.2–2 mm wide with l:w = 30–50 in typical subsp. sclerosperma; 6–9 (–11) cm long, 3–5 mm wide with l:w = (8–) 15–30 (–40) in subsp. sclerosperma (island variant 1); 4–7 cm long, 2–4 mm wide with l:w = (9–) 15–30 in subsp. sclerosperma (island variant 2). Further study of the two island variants is needed.
Acacia sclerosperma subsp. sclerosperma is somewhat salt tolerant and is useful as a windbreak in coastal areas; it is not highly palatable to stock.
FOA Reference
Data derived from Flora of Australia Volumes 11A (2001), 11B (2001) and 12 (1998), products of ABRS, ©Commonwealth of Australia
Author
A.R.Chapman, B.R.Maslin
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