Acacia euthycarpa (J.Black) J.Black, Trans. & Proc. Roy. Soc. S. Australia 69: 310 (1945)
Shrub 2–4 m tall, occasionally a small tree to 10 m. New shoots glabrous. Branchlets occasionally pendulous (Gawler Ra. plants), glabrous. Phyllodes narrowly linear to oblanceolate, flat to terete, (15–) 20–100 (–135) mm long,1–6 (–7) mm wide, shortly acuminate with delicate, curved point, usually green to grey-green, sometimes scurfy, glabrous, 4-nerved in all, 1-nerved per face when flat, nerves not prominent and often impressed. Inflorescences 2–4(–6)-headed racemes, raceme axes commonly 1–4 mm long, sometimes reaching 12–17 mm, sometimes growing out at anthesis; peduncles 3–10 mm long, glabrous; heads globular to shortly obloid, (22–) 25–60 (–74)-flowered, golden. Flowers 5 –merous; sepals mostly free or very shortly united. Legumes linear, to c. 15 cm long, 3.5–7 (–8) mm wide, coriaceous or sometimes +/- crustaceous, glabrous. Seeds longitudinal, obloid to ellipsoid, 4–6 mm wide, dull to slightly shiny, dark brown to black, funicle 2–3-folded, entirely encircling the seed, dark reddish; aril clavate.
Occurs in S.A. from Mt Finke, Gawler Ranges, Eyre Peninsula, Kangaroo Island, the Barossa Ra. south to Goolwa, and eastwards through the Murray Mallee to north-western Victoria (including Mt Arapiles).
Acacia euthycarpa is a member of the ‘ Acacia microbotrya group’ and has until now been treated as conspecific with its very close relative, A. calamifolia . However, A. calamifolia is distinguished its united sepals, +/- moniliform and woody to crustaceous legumes, often longer racemes, and consistently narrow phyllodes. Both species occur in S.A. but A. calamifolia extends to N.S.W. and A. euthycarpa extends to Victoria.
G.J.Leach & T.Wiffen, Bot. J. Linn. Soc. 76: 53–69 (1978), have shown A. x grayana to be a hybrid between A. brachybotrya and A. calamifolia (the latter parent is now known to be A. euthycarpa ). Specimens of A. euthycarpa with short, broad phyllodes are distinguished (rather arbitrarily) from A. x grayana by their glabrous new shoots and peduncles. The name A. microcarpa var. linearis (which is now considered synonymous with A. x grayana ) is often found on these specimens of A. euthycarpa .
Putative hybrids between A. calamifolia and A. wattsiana (Nectar Brook variant) may superficially resemble A. euthycarpa. Some individuals of this species superficially resemble A. retinodes var. uncifolia but are distinguished by a generally inland distribution, longer, more narrow dark green phyllodes, and darker yellow flowers on short racemes.
This species exhibits a perplexing range of variation in S.A.; the Eyre Penin. is an area of considerable complexity. Additional to the variation in phyllode shape and size, three habit variants can be recoginzed:
1. Wispy plants with pendulous branchlets from the Gawler Ra. and adjacent dunes, S.A.
2. Substantial trees to 10 m high, from central Eyre Peninsula, eastern Mt. Lofty Ranges near Saunders Creek, S.A., and from the Wedderburn- Wychitella district, Vic. (see A.B.Court, in J.H.Willis, Handb. Pl. Victoria 2: 220, 1973).
3. Rounded shrubs with blue-grey foliage, often associated with seasonally wet sites, from Eyre Peninsula, S.A. to Victoria.
Type of accepted name
Port Lincoln, S.A., 10 Oct. 1909, H.H.D.Griffith ; syn: AD; Nuriootpa, S.A., 8 Jan. 1912, herb. J.M.Black ; syn: AD; Barossa Ranges, S.A., Nov. 1912, herb. J.M.Black ; syn: AD; Arno Bay, S.A., July 1911, J.W.Mellor ; syn: AD; Karoonda, S.A., 5 Oct. 1915, herb. J.M.Black ; syn: AD; Lameroo, S.A., 15 Oct. 1918, herb. J.M.Black ; syn: AD.
Acacia calamifolia var. euthycarpa J.M.Black, Trans. & Proc. Roy. Soc. S. Australia 47: 369 (1923); A. euthycarpa (J.M.Black) J.M.Black, Trans. & Proc. Roy. Soc. S. Australia 69: 310 (1945). Type: Port Lincoln, S.A., 10 Oct. 1909, H.H.D.Griffith ; syn: AD; Nuriootpa, S.A., 8 Jan. 1912, herb. J.M.Black ; syn: AD; Barossa Ranges, S.A., Nov. 1912, herb. J.M.Black ; syn: AD; Arno Bay, S.A., July 1911, J.W.Mellor ; syn: AD; Karoonda, S.A., 5 Oct. 1915, herb. J.M.Black ; syn: AD; Lameroo, S.A., 15 Oct. 1918, herb. J.M.Black ; syn: AD.
[ Acacia microcarpa var. linearis auct. non J.M.Black: J.H.Willis, Victorian Naturalist 73: 156 (1957), as to Mannum specimen, fide B.R.Maslin, Nuytsia 6: 39 (1987)]
S.A.: Gawler Ra., R.Bates 3369 (AD); Ferries – McDonald Conservation park, c. 16 km due SW of Murray Bridge, B.R.Maslin 5973 (AD, MEXU, PERTH); Kangaroo Island; roadside near Birchmore Lagoon (ca 20 km SW of Kingscote), Hj.Eichler 15446 (AD, PERTH); W edge of Lake Malata, just where road from S approaches close to the banks, Eyre Peninsula, D.E.Symon 11785 (AD, PERTH). Vic.: c. 11 km N of Wedderburn P.O., A.C.Beauglehole 50163 (MEL).
(BRM & MO’L)
In Fl. Australia this species was included within A. calamifolia .