Acacia effusifolia Maslin & Buscumb
WATTLE
Acacias of Australia
Family
Fabaceae
Distribution
Widespread from near Mullewa and N of Cleary (Cleary is c. 100 km E of Dalwallinu) NE to near Meekatharra, Barwidgee Stn (c. 85 km SE of Wiluna) and near Lake Goongarrie (which is c. 40 km S of Menzies); with an outlier S of Wannoo (c. 155 km N of Northampton) and at Mt Channar (c. 35 km SE of Paraburdoo), W.A. This distribution encompasses the ranges of the two variants recognised within this subspecies. The pedunculate-head variant has essentially the distribution of the subspecies; the sessile-head variant occurs predominantly from near Mullewa and near Yalgoo (Yalgoo is c. 115 km ENE of Mullewa) SE to N of Cleary, with outliers S of Wannoo and E at Comet Vale (c. 100 km NNW of Kalgoorlie).
Description
Shrub or tree 2–5 m high, stems with few to many, shallow to deep longitudinal flutings. Bark smooth, rarely fissured near the base. New shoots resin-encrusted, with sparse, reddish, glandular hairlets on young phyllodes. Branchlets resin-ribbed, appressed-hairy between ribs. Phyllodes narrowly linear, flat, straight to shallowly curved, (4–) 6–10 (–14) cm long, (1–) 1.5–3 (–4) mm wide, acute, subrigid, green to grey-green or glaucous, glabrous or minutely appressed-hairy between nerves; longitudinal nerves fine, numerous and close together. Inflorescences simple, mostly 2 per axil; peduncles 1–6 (–8) mm long, ±densely silvery-white appressed puberulous and with normally sparse, red-brown glandular hairlets; heads short-obloid to cylindrical, 5–15 (–20) mm long, 4–7 mm diam., golden. Flowers 5-merous; sepals free to ¼ united, ½–2/3 length of petals. Pods straight to slightly curved, terete, (2–) 3–7 (–9) cm long, 1–2 mm wide, thinly coriaceous-crustaceous, ±obscurely longitudinally nerved. Seeds longitudinal, oblong, 3–4 mm long, shiny, brown; aril white.
Phenology
Flowers mostly July–Sept.
Habitat
Grows mostly in variously coloured sands or loam, often with a high clay content, on sandplains or flats, and on low hills and granite outcrops, in spinifex and shrubland with various Eucalyptus and Acacia species.
Specimens
W.A.: 58.9 km S of Overlander Roadhouse on North West Coastal Hwy, M.E.Ballingall 1892 (CANB, PERTH); Karara Station, J.S.Beard 7196 (PERTH); 29 km W of Yalgoo towards Mullewa, B.R.Maslin 3622 (BM, BRI, G, K, MEL, NSW, NY, PERTH); Sturt Meadows, Leonora district, Nov. 1973, R.F.Maslin (CANB, K, MEL, PERTH); 78 km N of Kalgoorlie towards Menzies, D.Pearson DJP345 (PERTH).
Notes
Until recently this taxon was treated as a variety of A. coolgardiensis but is now considered more appropriate as a distinct species; see B.R.Maslin & C.Buscumb, Nuytsia 18: 107–125 (2008) for discussion.
R.S.Cowan & B.R.Maslin, Nuytsia 10: 22 (1995) and subsequently R.S.Cowan, Fl. Australia 11B: 330 (2001) recognised two variants based on peduncle length; this now appears unlikely.
A member of the ‘A. coolgardiensis group’, most closely related to A. coolgardiensis. Also related to A. thoma and superficially resembling A. ramulosa var. ramulosa which differs in its generally straighter, greener and more rigid phyllodes, peduncles lacking red-brown glandular hairlets and broader pods.
FOA Reference
Data derived from Flora of Australia Volumes 11A (2001), 11B (2001) and 12 (1998), products of ABRS, ©Commonwealth of Australia
Author
R.S.Cowan
Revised by B.R.Maslin & J.Reid
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