Acacia nigricans (Labill.) R.Br., in W.T.Aiton, Hortus Kew . 2nd edn, 5: 465 (1813) —as to name only
Shrub 0.5- 1.5 m high. Branchlets ribbed, hirsutellous to hirsute, occasionally pilose or subglabrous, the hairs tubercle-based. Stipules patent. Pinnae mostly 2 pairs, 2- 4 mm long (proximal pinnae), 5- 15 mm long (distal pinnae); apex slightly or prominently recurved; rachis 3- 9 mm long; pinnules 2 pairs (proximal pinnae), 3- 8 pairs (distal pinnae), oblong to narrowly oblong, 3- 8 mm long, 1.5- 4 mm wide, flat or recurved, green, glabrous or subglabrous; gland on rachis 0- 2 mm below pinnae, sessile, prominent. Inflorescences 2-headed racemes, 1- 3 per axil; raceme axes 0.5- 2 mm long; peduncles 8- 12 mm long, glabrous; heads globular, 11- 26-flowered, pale yellow. Flowers 5-merous; sepals c. 3/4-united; petals 1-nerved. Pods 1.5- 3.5 cm long, 5- 6 mm wide, normally glabrous. Seeds oblique, oblong to elliptic, 2.5- 3 mm long.
Coastal areas (including islands of Recherche Archipelago) from Barker Inlet (50 km W of Esperance) E to near Israelite Bay, extending inland to Howick Hill, southern W.A. Grows on sand dunes and flats and lower granitic slopes, in heath and scrub.
The complex nomenclatural history of A. nigricans , which is linked to that of A. leioderma , is discussed by B.R. Maslin, Nuytsia 1: 440 (1975).
A member of the ‘ Acacia browniana group’ distinguished from the more westerly distributed A. browniana , A. leioderma and A. empelioclada by its reduced, binate racemes, see B.R.Maslin, loc. cit. , for further discussion.
Type of accepted name
south western Australia [Esperance, W.A.], herb. Webbianum ex herb. Labillardiere; lecto: FI, fide B.R.Maslin, Nuytsia 1: 438 (1975); isolecto: B, FI, P, RO, TCD.
Synonymy
Mimosa nigricans Labill., Nov. Holl. Pl. 2: 88, t. 238 (Mar. 1807), non Vahl (1807); Acacia rutaefolia Link, Enum. Hort. Berol. Alt. 2: 444 (1822), nom. illeg. (based by implication on A. nigricans ). Type: as for accepted name.
Acacia ignorata K.Koch, Allg. Gartenzeitung 26: 195 (1858); A. pentadenia hort. ex K.Koch, loc. cit. , pro syn., non Lindl. (1832). Type: none cited, based on a cultivated specimen; n.v.
[ Acacia obscura auct. non A.DC.: G.Bentham, Fl. Austral. 2: 418 (1864) p.p. , as to R.Brown , Goose Island Bay].
Illustrations
J.J.H.de Labillardiere, loc. cit. ; B.R.Maslin, Nuytsia 1: 439, fig. 16 (1975).
Representative collections
W.A.: Goose Is. Bay, 1803, R.Brown ‘4330’ (BM, E); Barker Inlet, E.M.Canning 7027 (CANB); 4 km from Esperance towards Albany, B.R.Maslin 5835 (AD, MEL, PERTH); Howick Hill, B.R.Maslin 6108 (PERTH); Middle Is., Recherche Archipelago, 22 Nov. 1950, J.H.Willis (MEL).
(BRM)
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.
