Acacia dealbata Link, Enum. Hort. Berol. Alt. 2: 445 (1822)
Silver Wattle
Bushy shrub or spreading tree to 30 m high. Bark smooth, grey, brown or dark brown, deeply corrugated when old. Branchlets slightly angular with ridges, densely puberulous. Young foliage-tips white, cream-coloured to golden, velvety-tomentose. Leaves herbaceous, bluish grey or silvery, glaucous; petiole to 1.5 cm long, slightly ridged, with apical gland; rachis 1–12 (–16) cm long, with one orbicular, light to dark brown, tomentellose, jugary gland at each pair of pinnae, interjugary glands absent; pinnae 6–30 pairs, 0.5–5.5 cm long; pinnules 10–68 pairs, narrowly oblong to linear, 0.7–6 mm long, 0.4–0.8 (–1) mm wide, upper surface ±glabrous or puberulous, lower surface silvery-puberulous, apex obtuse or truncate. Inflorescences in axillary racemes, or mostly terminal or axillary false-panicles; axes often zig-zagged. Heads 13–42-flowered. Pods often slightly constricted between some or all seeds, 2–11.5 cm long, 6–14 mm wide, subcoriaceous, blue or purplish, pruinose.
Occurs in N.S.W. on the tablelands from Guyra S to Tom Groggin and on the western slopes from Mudgee S to Albury, widespread in Vic. and eastern Tas., naturalised in south-eastern S.A. and south-western W.A. Grows mostly in open or tall open forest or woodland, at high altitudes often in low vegetation in subalpine areas, also in deep gullies and on swamp margins.
Specimens of A. leucoclada have been confused with A. dealbata in the past.
Acacia dealbata occasionally hybridizes with A. baileyana and possibly also A. pataczekii . Hybrids with A. podalyriifolia have been described as A . x hanburyana .
There are 2 subspecies and intermediates between them are common in areas where subsp. dealbata occupies the lower mountain slopes and subsp. subalpina the upper slopes.
Pinnae mostly 1.5–5.5 cm long; leaves mostly 5–12 cm or more long; pinnules 1.5–6 mm long; heads 22–42-flowered; tree to 30 m high, occasionally a shrub
subsp. dealbata
Pinnae 0.5–2.5 (–3) cm long; leaves mostly 1.5–8.5 cm long; pinnules mostly 0.7–4 mm long; heads 13–34-flowered; shrub or tree to 5 m (or rarely 10 m) high
subsp. subalpina
Acacia dealbata Link subsp. dealbata
Shrub or spreading tree to 30 m high. Leaves (3–) 5–12 (–17) cm long, slightly to very glaucous; pinnae 10–26 (–30) pairs, mostly 1.5–5.5 cm long; pinnules (14–) 20–68 pairs, 1.5–5 (–6) mm long. Heads 22–42-flowered, yellow. Pods to 11.5 cm long. 2 n = 26, B.G.Briggs, on E.F.Constable s.n. (NSW107046).
Extends along the Great Dividing Ra. from Ben Lomond Ra., northern N.S.W., to the Grampians, Vic., usually from 350–1000 m alt., common in Tas. Occasionally naturalised in the Adelaide Hills (Southern Lofty region) and around Penola, fide D.J.E.Whibley & D.E.Symon, Acacias S. Australia 2nd edn, 304 (1992), as well as in south-west W.A. Grows in open forest or woodland or tall open forest, on high plateaux or in deep gullies. Flowers Aug.–Oct.; fruits Nov.–Jan., sometimes to Mar.
Type of accepted name
Not cited; holo: B (destroyed in World War 2). A neotype needs to be chosen.
Synonymy
Acacia decurrens var. dealbata (Link) F.Muell. ex Maiden, Wattles & wattle-barks 3rd edn, 39 (1906); Racosperma dealbatum (Link) Pedley, Austrobaileya 2: 358 (1987). Type: as for accepted name.
Acacia decurrens B [var.] mollis Lindl., Bot. Reg. 5: t. 371 (1819). Type: not designated; 'Native of Van Diemen's Island. ...... The drawing was taken from a sample sent from Lord Bridgewater's ccollection in February last' in protologue. (J.P.M.Brenan & R.Melville, Kew Bull. 14: 37–41 (1960) placed A. decurrens (Wendl.) Willd. var. mollis Lindl. in synon. under A. mearnsii ).
Acacia puberula Dehnh., Cat. Horti camald ., 2nd edn: 17 (1832). Type: not designated [protologue gives ‘Nov. Holl. Flor. Februar. Mart.’; there are several ?Dehnhardt specimens which may possibly be of type significance at NAP (photo NSW, PERTH)].
Acacia derwentii hort. ex Siebert & Voss, Vilm. Blumengartn . 3rd edn, 1: 228 (1894), in synon .
Doubtful name
Acacia dealbata var. mackayana Seem.: see Doubtful Names.
Illustrations
J.H.Maiden, Forest Fl. New South Wales 3: pl. 88H - N (1907); M.Simmons, Acacias Australia 2: 303 (1988); D.J.Boland et al ., Forest Trees of Australia 4th edn, 159 (1984); D.J.E.Whibley & D.E.Symon, Acacias S. Australia 2nd edn, 305 (1992).
Representative collections
S.A.: Crafers, Mt Lofty Ra., E.S.Booth 176 (AD, NSW). N.S.W.: 32.2 km N of Guyra, Ben Lomond Ra., J.S.Beard 936 (NSW); Bowral - Robertson road, 6 Sept. 1960, M.D.Tindale s.n. (NSW). A.C.T.: along Brindabella road near Cotter Dam, R.D.Hoogland 8555 (CANB, NSW). Vic.: Mt Langi Ghiran, E of Ararat, M.G.Corrick 7453 (MEL, NSW); on road to Lake Mtn near Alpine Reserve, D.B.Foreman 1045 (MEL, NSW). Tas.: Dee Lagoon, K.Hill 1502, L.A.S.Johnson & D.Blaxell (NSW).
Acacia dealbata subsp. subalpina Tindale & Kodela (ms), to be published in Telopea 9(2), (2001)
Dense shrub or tree to 3 m (rarely to 10 m) high; canopy often flat-topped. Leaves mostly 1.5–8.5 cm long, glaucous; pinnae (4–) 6–20 (–22) pairs, 0.5–2.5 (–3) cm long; pinnules 10 - 37 pairs, 0.7–3 (–4) mm long. Heads 13–34-flowered, bright yellow. Pods to 9.5 cm long. 2 n = 26, B.G.Briggs, on M.Gray & M.D.Tindale (NSW64114); 3 n = 39, B.G.Briggs, on M.Gray & M.D.Tindale (NSW64113).
Occurs mainly at higher altitudes of the tablelands from the Brindabella Ra. - Braidwood area, N.S.W. and A.C.T., to Mt Disappointment, north-eastern Vic.; common on the Snowy Mtns. Grows in tall open forest, open forest, woodland or tall woodland, on mountain ridges, steep and gentle slopes, in gullys and near creeks. Flowers mainly Aug.–Nov.; fruits Nov.–Feb. (–Apr.)
Type of accepted name
Tinderry Mtns, 13.2 km by road ESE of Michelago, N.S.W., 2 Aug. 1975, R.T.Coveny 6589, P.D.Hind & M.Parris ; holo: NSW; iso: A, AD, BRI, CANB, HO, K, MEL, MO, NE, NY, PERTH, UC, US, Z.
Representative collections
N.S.W.: 0.5 km due NE of Wyanbene Caves Mtn Trig., P.G.Kodela 119 (CANB, MEL, NSW). A.C.T.: c. 8 mi. [12.9 km] S of Gudgenby R. crossing on the Naas–Cooma road, R.Pullen 3060 (CANB, NSW). Vic.: Mt Disappointment, J.S.Beard 912 (NSW); Mt Delegate, H.van Rees 084 (MEL, NSW).
(PGK & MDT)
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.
