Acacia pycnantha Benth., London J. Bot. 1: 351 (1842)
Golden Wattle , Broad-leaved Wattle
Shrub or tree usually 3–8 m high. Branchlets sometimes pruinose, glabrous. Phyllodes often pendulous, falcately recurved to oblanceolate, pulvinus 4–7 mm long, much-narrowed at base, normally 9–15 cm long and 10–35 mm wide, obtuse to acute, coriaceous, glabrous, with prominent midrib, penninerved; gland often slightly exserted, sometimes 2, the lowermost 3–45 mm above pulvinus. Inflorescences racemose; raceme axes 2.5–9 cm long, stout, glabrous; peduncles 3–6 mm long, stout, glabrous; heads showy, globular to obloid, densely 40–80-flowered, bright golden, sometimes lemon yellow; bracteoles evident in buds; laminae subcircular, <0.5 mm diam., dark brown to blackish, white-fimbriolate. Flowers 5-merous; sepals united. Pods linear, 5–13 cm long, 5–7 mm wide, firmly chartaceous to thinly coriaceous, glabrous. Seeds longitudinal, oblong, 5.5–6 mm long, somewhat shiny, black; aril clavate.
Widespread and often locally common in Vic., extending W to the Flinders Ra., Yorke Penin., southern Eyre Penin. and Kangaroo Is., S.A.; isolated occurrences in southern N.S.W. and also from the Broken Hill area; near Canberra in the A.C.T. Naturalised in south-western W.A. and eastern Tas.; regarded as a weed species in parts of South Africa. Grows in sand or loam, in Eucalyptus forest or woodland, open scrub and heath.
A somewhat variable species. It is normally a tall shrub or tree, but small, spindly forms which flower when 0.5–1 m high sometimes occur (e.g. some plants in the Bendigo ‘Whipstick’ forest, Vic.). Plants with pruinose branches are scattered throughout the range (e.g. the most northerly populations in S.A.). L.F.Costermans, Native Trees & Shrubs SE Australia 317 (1981), records two forms for Vic., namely, plants from open forests with dark green shiny phyllodes and golden flower-heads, and plants from mallee areas with paler, dull, narrower phyllodes and paler coloured flower-heads.
Sometimes confused with A. obliquinervia , A. leiophylla or A. saligna . The allied species A. pedina from the South Coast of N.S.W. was recently described by P.G.Kodela & T.M.Tame, Telopea 8: 305 (1999); it is distinguished from A. pycnantha by having straight to shallowly recurved, oblanceolate to obovate adult phyllodes, large juvenile and intermediate phyllodes and 25-40-flowered heads.
Putative natural hybrids between A. pycnantha and A. williamsonii occur in the Bendigo ‘Whipstick’, Vic. (e.g. B.R.Maslin 5852 , MEL, PERTH). These hybrids superficially resemble A. hakeoides . Other putative hybrids of cultivated origin involving A. podalyriifolia are noted under A. podalyriifolia .
The bark is one of the richest sources of tannin in the world, although it is now rarely used commercially; the timber is tough and close-grained; the gum was eaten by Aborigines (see G.M.Cunningham et al. , Pl . W New South Wales 370 (1981), for references). Acacia pycnantha is the official floral emblem of Australia.
A fast growing, rather short-lived, somewhat frost-sensitive species which is widely planted as an ornamental, especially on account of its profusion of strongly perfumed, golden flower-heads. A pendulous variant and a pale-headed variant are known in cultivation, fide W.R.Elliot & D.L.Jones, Encycl . Austral. Pl. 2: 103 (1981). The species is an environmental weed in South Africa, fide C.H.Stirton (1978), Plant Invaders 56- 59 (Dept. Nature & Environmental Conservation, Cape Town).
Type of accepted name
Interior of New Holland [between the Loddon R. and Pyramid Hill, Vic.], 5 July 1836, T.L.Mitchell 222 ; ?holo: CGE.
Acacia leiophylla Benth., London J. Bot. 1: 351 (1842) p.p. , not as to lectotype, fide B.R.Maslin & D.J.E.Whibley, Nuytsia 2: 163 (1977).
Acacia petiolaris Lehm., in C.F.E.Otto, Neue Allgemeine Deutsche Garten-und Blumenzeitung 7: 210 (1851), also published by J.G.C.Lehmann in Ind. Sem. Hort. Bot. Hamburg 7 (Dec. 1851); A. pycnantha var. petiolaris H.Vilm., J. Roy. Hort. Soc . ser. 2, 16: 85 (1893)—?based on A. petiolaris . Type: cultivated at Hamburg Botanic Garden from seed said to have come from the Swan River colony, W.A. [provinence presumably incorrect]; n.v. , however, a specimen at K is possibly from the type plant, viz . ‘Acacia petiolaris Lehm! Hort. Bot Hamburg , 1852’. Synonymy following G.Bentham, Fl. Austral. 2: 365 (1864).
Acacia falcinella Meisn., Bot. Zeitung (Berlin) 13: 11 (1855), non I.F.Tausch (1836). Type: circa Victoria (Port Lincoln), Australia, C.J.Latrobe; n.v. Synonymy following G.Bentham, Fl. Austral. 2: 365 (1864).
Acacia westonii Maiden (as ‘Westoni’), J. & Proc. Roy. Soc. New South Wales 54: 227 (1921). Type: Mt Jerrambomberra, Queanbeyan, N.S.W., Aug. 1917, C.Weston ; syn: NSW; Mt Jerrambomberra, N.S.W., Mar. 1917, C.Weston ; syn: NSW.
J.H.Maiden, Forest Fl. New South Wales 3: pl. 107 (1907); G.M.Cunningham et al. , Pl . W New South Wales 370 (1981); L.F.Costermans, Native Trees & Shrubs SE Australia 317 (1981); T.Tame, Acacias SE Australia 129, fig. 135, pl. 135 (1992); D.J.E.Whibley & D.E.Symon, Acacias S. Australia 2nd edn, 165 & 167 (1992).
S.A.: Burra Ck gorge, 3 km W of Worlds End, B.R.Maslin 5993 (AD, PERTH); Alligator Ck, c. 45 km SE of Port Augusta, R.Hill 1027 (AD). N.S.W.: 8.7 km ENE of Bredbo on the Jerangle road, R.Coveny 5449 (MEL, NSW). A.C.T.: Mt Ainslie, Canberra, M.Gray 6437 (CANB, NSW). Vic.: between Benalla and Glenrowan, N.Hall H79/99 (MEL, NSW, PERTH).