Acacia retinervis Benth., London J. Bot. 1: 379 (1842)
Tree to 10 m high or shrub 2–5 m high. Bark fissured, grey-brown. New shoots resinous, scurfy, rusty-brown or sometimes with dense, silver, appressed to subappressed hairs. Branchlets terete, light brown to reddish, glabrous or sometimes with appressed or spreading hairs. Phyllodes falcate to subfalcate, 7–14 cm long, 6–25 mm wide, glabrous or occasionally sericeous, with 3–5 prominent longitudinal veins, the minor veins crowded, often almost touching, closely reticulate with narrow, obscure, elongated vein-islands. Inflorescences simple or rarely racemose (racemes to 20 mm long); spikes 1.5–5.5 cm long, usually 2 per axil, yellow. Flowers 5–merous; calyx deeply lobed, villous; ovary pubescent. Pods linear, tapering at each end, straight, 3–10.5 cm long, 5–9 mm wide, woody, glabrous, grey and longitudinally furrowed when dry. Seeds oblique, broadly elliptic, 5–6 mm long, black; areole oblong–elliptic, closed; aril cream.
Endemic to the north–western Kimberley region of W.A. where it occurs on numerous off–shore islands, extending inland to the Mitchell Plateau and Prince Regent River region. Most commonly associated with sandstone rock outcrops. Flowers May–July.
A. retinervis belongs to a group of closely related species which includes A. brassii , A. difficilis , A. tumida , A. mountfordiae ; this group is currently under review and additional new taxa will be recognised. A. retinervis is distinguished from these taxa in having phyllodes with crowded, closely reticulate minor veins (vein-islands obscure), mostly simple inflorescences and linear, woody pods. Acacia seclusa appears to be morphologically intermediate between A. tumida and A. retinervis .
A distinctive variant of uncertain rank, not included in the above description, has been commonly confused with typical A. retinervis . It is also endemic to the northern Kimberley region but extends from Cape Londonderry S to the Carson Escarpment region. It mainly differs in having elliptic to dimidiate, often pruinose phyllodes with a more open reticulum (i.e. vein-islands larger than in typical A. retinervis ) and broader, shorter pods (2.5–7.5 cm long, 7–14 mm wide). It is represented by the specimens B.Barnsley 1561 (CANB, NSW, PERTH), K.F.Kenneally 4383 (BRI, PERTH) and M.McDonald 329 (PERTH). This taxon is keyed and described separately in WATTLE under A. affin. retinervis .
Type of accepted name
Cape Pond, [W.A.], A.Cunningham ; syn: K, NSW; Isle Lacrosse, [W.A.], A.Cunningham ; syn: n.v. ; possible syntypes: Cape Pond to Rat Islands [probably Bat Island], [W.A.], 1820, A.Cunningham 291 (BM n.v. , photo NSW); Bat Island, [W.A.], Sept 1820, A.Cunningham 291 (K).
Illustration
J.R.Wheeler, J.R.Wheeler (ed.) et al ., Fl. Kimberley Region 316, fig. 91H (1992).
Representative collections
W.A.: Mitchell Plateau, near camp, NW Kimberley, J.S.Beard 8233 (PERTH); unnamed tributary of the Prince Regent R., N Kimberley, K.F.Kenneally 8904 (NSW, PERTH); Naturalist Is., in Prince Frederick Harbour, W of entrance of Hunter R., K.F.Kenneally 9924 (BRI, PERTH); Crystal Ck, SW of Crystal Head, Admiralty Gulf, M.McDonald 340 (PERTH); Sir Graham Moore Is., P.G.Wilson 11344 (AD, NSW, PERTH).
(MWM, PGK)
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.
