Acacia myrtifolia (Sm.) Willd., Sp. Pl. 4th edn, 4: 1054 (1806)
Myrtle Wattle , Red Stem Wattle (Red-stemmed Wattle) , South Australian Silver Wattle
Glabrous, bushy shrub usually 0.5–3 m high. New shoots often red. Branchlets angled, prominently ribbed, normally red. Stipules early caducous. Phyllodes erect, oblique, commonly narrowly elliptic to oblanceolate, sometimes linear to linear-elliptic, normally 2–13 cm long, usually 4–30 mm wide, acute or obtuse-mucronate, sometimes coarsely pungent, usually thick and coriaceous, smooth, green; midrib and marginal nerves prominent; lateral nerves absent or obscure; gland prominent, mostly 0.5–2 cm above pulvinus. Inflorescences 3–20-headed racemes; racemes axes 1–6 (– 12) cm long; peduncles 3–12 mm long, stout; heads globular, 2–5-flowered, sometimes to 8-flowered, usually creamy yellow. Flowers 4-merous, large; sepals united into a truncate to sinuolately lobed calyx; ovary tomentulose. Pods erect, linear, curved, to 9 cm long, 3–5 mm wide, crustaceous to subwoody; marginal nerve thick, undulate. Seeds longitudinal, narrowly oblong, 3.5–4.5 mm long, shiny, brown or greyish brown; aril terminal.
Widespread and common in temperate southern Australia, occurring in all States, except N.T. Grows in sand or sand over laterite or granite, in forest, woodland, scrub or heath, often in coastal or near-coastal areas. The distribution pattern of A. myrtifolia resembles the combined distributions of A. subcaerulea and A. suaveolens .
In W.A. this is a somewhat variable species and is here broadly circumscribed because detailed analyses of variation patterns are needed to ascertain appropriate ranks for the variants noted below. Specimens from forest regions at the western end of the range (roughly W of Albany; also some specimens from Kangaroo Is., S.A.) have long, linear to very narrowly elliptic phyllodes with l:w mostly >10 (elsewhere l:w is <10). This variant has been described as A. marginata , A. myrtifolia var. angustifolia and A. acutifolia (see below). A specimen with especially large phyllodes (to 13 x 3.5 cm) collected from Cape Riche (i.e. K.Newbey 4466 , PERTH) presumably corresponds to the entity described as A. myrtifolia var. major . The most inland specimens in W.A. have bright lemon yellow heads (e.g. Bendering Reserve, c. 18 km due ENE of Bendering Siding, B.R.Maslin 5765 , CANB, K, MEL, NY, PERTH) but elsewhere in W.A. the heads are creamy yellow; in eastern Australia the flower-heads are also sometimes bright lemon yellow. A prostrate variant of A. myrtifolia is recorded for the Sydney region by T.D.Auld & D.A.Morrison, Austral. J. Bot. 40: 1–11 (1992).
As discussed by B.R.Maslin, Nuytsia 10: 99 (1995), it is likely that the type locality, and probably also the other collecting details, given in the protologue of A. acutifolia are erroneous. This name is referable to the long phyllode variant of A. myrtifolia from W of Albany.
Acacia myrtifolia together with eight close relatives from W.A., namely, A. celastrifolia , A. clydonophora , A. disticha , A. durabilis , A. heterochroa , A. nervosa , A. obovata , and A. pygmaea comprise the ‘A. myrtifolia group’, fide B.R.Maslin, op. cit. 85–86. Acacia gilbertii (leaves bipinnate) should probably also be added to this group, fide P.Guinet et al. , Bot. J. Linn. Soc. 80: 53–68 (1980). Acacia urophylla and A. scalpelliformis are not far removed from the ‘A. myrtifolia group’ even though they have more than one nerve per phyllode, see J.Vassal, Bull. Soc. Hist. Nat ., Toulouse 108: 1–127 (1972).
This fast growing and attractive ornamental was one of the earliest Australian plants in cultivation in Europe.
Type of accepted name
Cultivated at Sion Gardens, seed from N.S.W., flowered 1790, T.Hoy ; n.v. (a specimen at K, ex herb. Bishop Goodenough, labelled ‘Mimosa myrtifolia . Botany Bay—1794’ was cited as isotype by L.Pedley, Austrobaileya 1: 258 (1980) even though this was seemingly collected three years after the publication of the name).
Mimosa myrtifolia Sm., Trans. Linn. Soc. London 1: 252 (1791); Phyllodoce myrtifolia (Sm.) Link, Handbuch 2: 133 (1831); Cuparilla myrtifolia (Sm.) Raf., Sylva Tellur. 120 (1838). Type: as for accepted name.
Acacia marginata R.Br., in W.T.Aiton, Hortus Kew . 2nd edn, 5: 462 (1813); Mimosa marginata (R.Br.) Poir., Encycl. Meth. (Bot.) Suppl. 5: 530 (1817), nom. inval. (combination not actually made); A. myrtifolia f. angustifolia Benth., Fl. Austral. 2: 377 (1864); A. myrtifolia var. angustifolia (Benth.) Benth., Trans . Linn . Soc . London 30: 475 (1875). Type: ‘Mimosa .’ King George III Sound [Albany, W.A.], Dec. 1801, R.Brown; lecto: BM, upper left hand fruiting specimen on sheet titled ‘Iter Australiense, 1802- 5’ and bearing [Britten no.] 4336 , fide B.R.Maslin & R.S.Cowan, Nuytsia 10: 115 (1995); isolecto: K.
Acacia trigona A.DC., Huitieme Not. Pl. Rar. Geneve 20 (1840); Mem. Soc. Phys. Geneve 9: 94 (1841). Type: ‘Culta in hortis Genevensibus. Floret Maio.’; n.v. , however, the following specimen at G, collected one year after the original publication of this name, and annotated ‘trigona’ by A.P.de Candolle, was likely to have come from the type plant ‘Acacia trigona Alph. DC.! h. genev. notii. Cult. Genev. 1841’.
Acacia marginata var. angustata Meisn., in J.G.C.Lehmann, Pl. Preiss . 1: 14 (1844). Type: Mt Clarence [Albany], W.A., 30 Sept. 1840, L.Preiss 927 , ex parte ; lecto: LD, fide B.R.Maslin & R.S.Cowan, Nuytsia 9: 408 (1994); isolecto: A, C, FI, G, GOET, HBG, K, M, MEL, NY, P, STR, W.
Acacia pawlikowskyana Ohlend., Neue Allg. Deutsche Garten-Blumenzeitung 1: 369 (1845). Type: between Cape Riche and Bald Head [Albany], W.A., collector not given; n.v. Synonymy following B.R.Maslin, Nuytsia 10: 97 (1995).
Acacia myrtifolia var. major Meisn., in J.G.C.Lehmann, Pl. Preiss. 2: 203 (1848). Type: Cape Riche, W.A., L.Preiss 2641 ; n.v. Synonymy following B.R.Maslin, loc. cit.
Acacia marginata var. brevifolia Regel, Gartenflora 2: 196, t. 57 (1853). Type: [This valuable garden plant flowers in March–April in the cold-house and was obtained from Herr A. Napoleon Baumann , Bollwiller]; n.v. Synonymy following B.R.Maslin, loc. cit.
Acacia myrtifolia f. normalis Benth., Fl. Austral. 2: 377 (1864), nom. inval.
Acacia acutifolia Maiden & Blakely, J. Roy. Soc. W. Australia 13: 14; pl. 11, figs 1–4 (1928). Type: Bruce Rock- Merredin district, W.A., Dec. 1916, F.Stoward 14 [locality and other collecting details probably erroneous, fide B.R.Maslin, loc. cit. ]; holo: NSW; iso: MEL (Fragment ex NSW).
[ Acacia amoena auct. non H.L.Wendl.: F.M.Bailey, Queensland Fl . 2: 489 (1900), fide L.Pedley, Austrobaileya 1: 258 (1980)]
J.E.Smith, Spec. Bot. New Holland 53, t. 15 (1795); E.R.Rotherham et al. , Fl. & Pl. New South Wales & S Queensland 71 (1975); L.F.Costermans, Native Trees & Shrubs SE Australia 314 (1981); B.A.Lebler, Wildfl. SE Queensland 2: 58 (1981); T.Tame, Acacias SE Australia 143, fig. 154, pl. 154 (1992); D.J.E.Whibley & D.E.Symon, Acacias S. Australia 2nd edn, 153 (1992).
W.A.: near Spencer’s house [Strawberry Hill Farm, Albany], L.Preiss 920 (G, LD, MO, NY, P, STR). S.A.: Manning Reserve near MacLaren Flat, D.J.E.Whibley 1331 (AD). Qld: Kroombit Tops, c. 65 km SSW of Gladstone, W.J.F.McDonald 1014 (BRI). N.S.W.: Belmont North, T.Tame 2039 (PERTH). Vic.: Dandenongs, Menzies Ck area, J.H.Ross 2791 (AD n.v. , BRI n.v. , CANB n.v. , HO n.v. , MEL n.v. , PERTH). Tas.: Clarkes Is., Furneaux Group, J.S.Whinray 1692 (MEL).