Acacia willdenowiana H.L.Wendl., Verz. Berggart. Hannover 5 (1845)
Grass Wattle , Two-winged Acacia
Erect shrub 0.3–0.6 m high with a rush-like habit, sometimes to 1 m high or stems scrambling. Stipules minute. Phyllodes continuous with branchlets, bifariously decurrent forming opposite wings with each one extending to the next below, the wings 1–5 (- 15) mm wide, grey-green to glaucous, glabrous, rarely hairy; free portion of phyllode usually 5–20 mm long, acute, with a nerve close to upper margin; gland absent. Inflorescences racemose; raceme axes 2–11 cm long, commonly narrowly winged, if wings expand the peduncles appear simple and axillary; peduncles twinned, 6–15 mm long, glabrous; heads globular, 13–21-flowered, white, cream or pale lemon yellow; buds normally acute to subacute. Flowers 5-merous; sepals united. Pods curved, flat, to 6 cm long, 10–15 mm wide, thinly crustaceous, normally glabrous; margins thick. Seeds transverse, oblong, 5–6 mm long, arillate.
Sporadic from near Coorow S to near Stirling Ra. (Stirling Ra. is E of Cranbrook), south-western W.A. Grows in sand, loam and lateritic soils, often in winter wet depressions, usually in open woodland and woodland.
Phyllode width and head colour somewhat variable, see B.R.Maslin, Nuytsia 10: 168–169, for discussion.
Related to A. applanata with which it is sometimes sympatric or parapatric. A. alata differs in having a central main nerve and the free portion of the phyllode having 1–3 glands. Phyllodes sometimes resembling those of A. pterocaulon .
Type of accepted name
Swan R., W.A., 1839, J.Drummond s.n .; lecto: CGE, fide B.R.Maslin, Nuytsia 10: 166 (1995); isolecto: CGE, K; paralecto: see A. applanata .
Acacia willdenowiana is based on the following: Acacia diptera Lindl., Sketch Veg. Swan R. xv (1839), non Humb. & Bonpl. ex Willd. (1809); A. benthamii Heynh. (as ‘benthami’), Nom. Bot. Hort. 2: 2 (1846), non Meisn. (1844). Type: as for accepted name.
Acacia diptera var. erioptera Graham, Bot. Mag. 68: t. 3939 (before May 1842), non Bentham (about June 1842). Type: cultivated plant received in 1840 at Royal Botanic Gardens, Edinburgh, from Glasgow where it was raised from Swan River seeds sent by J.Drummond; n.v. , however, a specimen at E, probably from the type plant, is annotated by R.Graham ‘Acacia diptera var. erioptera Grah. Greenhouse R. Bot. Gard. Edin. 24 Decb. 1842.’, there is a probable duplicate of this specimen at K.
Acacia diptera var. erioptera Benth., London J. Bot . 1: 325 (about June 1842), nom. illeg . (later homonym). Type: Swan R., W.A., J.Drummond 182 ; syn: K; Swan R., W.A., J.Drummond s.n .; syn: K.
Acacia diptera var. latior Meisn., in J.G.C.Lehmann, Pl. Preiss . 1: 4 (1844); A. benthamii var. latior (Meisn.) Heynh. (as ‘Benthami’), Nom. Bot. Hort . 2: 2 (1846). Type: near Halfwayhouse [Halfway House, 31 54’S, 116 20’E], W.A., 12 Sept. 1839, L.Preiss 996 ; lecto: NY, fide B.R.Maslin & R.S.Cowan, Nuytsia 9: 405 (1994); isolecto: G, GOET, HBG, L, LD, STR; near Perth, W.A., 8 May 1839, L.Preiss 995 ; paralecto: B, FI, G, GOET, HBG, K, L, LD, NY—sphalm. ‘595’, P, STR)
W.J.Hooker, Icon. Pl. ser. 1, 4: t. 369 (1841); R.Graham, Bot. Mag. 68: t. 3939 (before May 1842); M.Simmons, Acacias Australia 2: 11 & pl. 36 (1988).
W.A.: Boonanarring Brook near Gingin, J.J.Alford 391 (PERTH); c. 64 km SW of Winchester on Coorow- Green Head road, 12 June 1974, C.Chapman (CANB, K, MEL, NSW, NY, PERTH); Cottesloe, 22 July 1897, R.Helms (PERTH); c. 30 km ENE of Mount Barker, 25 May 1983, P.Luscombe (K, PERTH); 16 km W of Harvey, B.R.Maslin 443 (MEL, PERTH).