Acacia brachystachya Benth., Fl. Austral. 2: 403 (1864)
Turpentine Mulga, Umbrella Mulga, Grey Mulga, False Bowgada
Shrub branched at base, to 5 m tall and wide. Branchlets with dense appressed hairs between dark resinous ribs; some red-glandular hairs on new growth. Phyllodes flat, occasionally subterete, straight, 4–11 cm, rarely to 18 cm, long, 1–3 mm wide, finely striate, appressed pubescent between longitudinal nerves. Inflorescences single in axils; peduncles 3–10 mm long; spikes 10–30 mm long. Flowers 5-merous; sepals oblong, 0.5–0.8 mm, rarely to 1 mm long, united in tube to 0.4 mm long or occasionally free, with long hyaline hairs on lobes; corolla 1.5–1.8 mm, rarely to 2 mm, long-pubescent to varying degrees; stamens to 3 mm long; ovary with dense appressed longish white hairs. Pods not stipitate, narrowly oblong in outline, straight, turgid, oval in section, to 7.5cm long, 4–6mm wide, dull brown with prominent yellowish resinous anastomosing longitudinal nerves, elsewhere appressed-pubescent, tardily dehiscent. Seeds longitudinal, oblong, 5–8 mm long, 3–5 mm wide; aril small, terminal, pileate, pale.
Occurring in all mainland States except Vic., from the extreme east of W.A., the south of N.T., much of S.A. to south-western Qld and north-eastern N.S.W.; often on sandy loam soils in association with A. aneura and on sandy soils between dunes or on degraded dunes. In the eastern part of its range it also occurs on shallow stony soils. Its ecological requirements are similar to those of A. ramulosa but it has a narrower geographic range. Specimens usually referred to A. brachystachya in the west of W.A. are for the most part, hybrids between A. aneura and A. ramulosa .
The closest relative of A. brachystachya is A. ramulosa from which it differs in its smaller pods which are oval in cross-section, its smaller flowers with petals with less dense and usually shorter hairs, and its usually narrower phyllodes. Also closely related to A. clelandii .
B.R.Randell ( J. Adelaide Bot. Gard . 14: 128, 1992) lectotypified A. brachystachya , though it could be argued that such lectotypification was unnecessary. She then treated the name as an ‘excluded name’. See Fl. Australia Appendix (in press) for reasons why the name is accepted here.
Type of accepted name
Mutanie [Mootawingie] Ra., N.S.W., Dr Beckler , Victorian Expedition; lecto: MEL, fide B.R.Randell, J. Adelaide Bot. Gard. 14: 128 (1992); isolecto: K.
Acacia aneura var. brachystachya (Benth.) Maiden, Wattle & Wattle Barks 3rd edn, 61 (1906); Racosperma brachystachyum (Benth.) Pedley, Austrobaileya 2: 345 (1987). Type: as for accepted name.
Acacia aneura var. (?) stenocarpa Benth., Fl. Austral 2: 403 (1864). Type: Yaginya Mtn [Scrope Ra., c. 65 km E of Broken Hill, N.S.W.], 6 Nov. 1860, [ Beckler ] Victorian Expedition; holo: K.
Acacia cibaria F.Muell., Australas. Chem. Druggist 5: 26 (July 1882). Type: Yayinya Mtns [sic], 6 Nov. 1860, Dr Beckler , Victorian Expedition; lecto MEL, fide B.R.Randell, J. Adelaide Bot. Gard. 14: 117 (1992); isolecto: K, NSW.
W.A.: Reid, June 1959, E.McCrumm s.n. (PERTH). N.T.: Rainbow Valley, D.E.Albrecht (BRI, DNA, MEL, NT). S.A.: Tarcoola, J.A.Mattner 50 (AD) & 21 Sept. 1920, E.H.Ising s.n. (AD); Stuart Hwy adjacent to Agnes Creek HS, B.Hadlow 271 & A.B.Court (CANB, NSW). Qld: 'Nerrigundah', W slope of Grey Ra., 60 km SW of Quilpy, L.Pedley 4203 (BRI). N.S.W.: White Cliffs road, P.E.Conrick 1471 (AD, MEL, PERTH).