Acacia papyrocarpa Benth., Fl. Austral. 2: 338 (1864)
Tall shrub or small tree 3–8 m high, with dense, neat, rounded, spreading crown. Bark fissured, grey. Branchlets occasionally pendulous, appressed-puberulous, glabrescent. Phyllodes linear, flat or sometimes subterete, 4–12 cm long, 1–3 mm wide, acuminate with a fine, delicately curved, innocuous point, not rigid, silvery appressed-puberulous, often glabrescent, with numerous closely parallel, indistinct nerves. Inflorescences rudimentary 2–5-headed racemes with axes c. 1 mm long or simple in axillary clusters; peduncles 2–7 mm long, silvery appressed-puberulous; heads globular, 3–4 mm diam., 20–25-flowered, golden; bracteoles oblanceolate, ciliate. Flowers 5-merous; sepals free to 1/3-united; petals glabrous. Pods narrowly oblong, flat, slightly raised over and constricted between seeds, to 11 cm long, 4–10 mm wide, chartaceous, reticulate, glabrous. Seeds longitudinal, broadly elliptic to ovate, 4.5–5 mm long, subnitid, dark brown; aril small.
Scattered in southern inland W.A. from near Kalgoorlie across the Nullarbor into S.A. as far as Mt Irwin Stn and South Flinders Ra. A flowering specimen from near Cooper Ck, Qld, is distributionally anomalous and may in fact not even represent this species. Grows in sandy loam, clay and calcareous soil, in low open woodland and shrubland, often with chenopods.
The collection, M.Koch 274 (comprising Oct. 1898, Sept. 1899 and Nov. 1899 specimens) (BM, DBN, K, M, NSW, PERTH) from Mt Lyndhurst, E of L. Torrens, S.A., appears not to be A. papyrocarpa , although it shares a number of characteristics with it. It differs principally in having nearly terete, rather rigid, longitudinally sulcate, coarsely pungent phyllodes and minutely appressed-puberulous pods with raised venation. It was this material, in part, on which J.Black based his description in Fl. S. Australia , 2nd edn, pt. 2: 423 (1948) of A. papyrocarpa . It was referred to as ‘A. sp. affin. papyrocarpa’ by B.R.Maslin, in J.P.Jessop (ed.), Fl. Central Australia 137 (1981). A specimen labelled ‘near Blythe Range, S.A. border, 1898’, W.V.Fitzgerald s.n. (PERTH00148385) appears to be the same taxon but as the locality is considerably removed from L. Torrens the occurrence should be confirmed. Koch’s Mt Lyndhurst collection probably represents the same taxon known from gullies along the W side of L. Torrens (e.g. Myall Well, Andamooka Stn, F.J.Badman 3277 , AD). In WATTLE this taxon is keyed and described separately, as A. affin. papyrocarpa .
In the area N of Port Augusta, S.A., a pendulous form, locally called Water Myall , occurs sympatrically with typical A. papyrocarpa .
Acacia papyrocarpa is difficult to distinguish from the more easterly distributed A. loderi which has narrower, non-reticulate submoniliform pods; it also tends to have narrower phyllodes and less hairy bracteoles. Intermediates between the two species are reported by D.J.E.Whibley & D.E.Symon, Acacias S. Australia 2nd edn, 218 (1992). Also related to A. sibilans .
Aspects of the biology of A. papyrocarpa are summarised in D.J.E.Whibley & D.E.Symon, op. cit. 220- 221.
Type of accepted name
Inlet XII South Coast [head of Spencer Gulf, S.A.], R.Brown [Britten no. 4343]; lecto: BM, fide , B.R.Maslin, J. Adelaide Bot. Gard. 2: 316 (1980); isolecto: PERTH (Fragment ex BM).
Acacia sowdenii Maiden (as ‘Sowdeni’), J. & Proc. Roy. Soc. New South Wales 53: 180; pl. 11, figs 7–10 (1920). Type: Port Augusta, S.A., Jan. 1907, J.H.Maiden s.n. ; holo: NSW; iso: K, PERTH (Fragment ex K).
J.H.Maiden, loc. cit ., as A. sowdeni ; R.Erickson et al. , Fl. & Pl. W. Australia 143 (1973), as A. sowdenii ; B.R.Maslin, in J.P.Jessop (ed.), Fl. Central Australia 123, fig. 160L (1981); A.A.Mitchell & D.G.Wilcox, Arid Shrubland Pl. W. Australia 282- 283 (1988); M.Simmons, Acacias Australia 2: 123 (1988); D.J.E.Whibley & D.E.Symon, Acacias S. Australia 2nd edn, 221 (1992).
W.A.: Mt Gibson Stn (between Wubin and Paynes Find), B.R.Maslin 4223 (PERTH); Great Victoria Desert, just S of Plumridge Lakes, B.R.Maslin 5712 (BRI, PERTH). S.A.: c. 27 km W of Port Augusta on Hwy 1, B.Copley 3165 (NSW, PERTH); c. 15 km W of Nullarbor HS, D.J.E.Whibley 4504 (PERTH). Qld: near Boongeena Ck, 10 km E of Cooper Creek, R.Bennett , 28 Aug. 1984 (BRI, PERTH).
(RSC & BRM)