Acacia lamprocarpa O.Schwarz, Repert. Spec. Nov. Regni Veg . 24: 86 (1927)
Trees 3–12 m tall. Bark yellow-brown, papery and flaky on stems and branches of young to medium-aged plants. Branchlets slender, often pendulous glabrous. Phyllodes dimidiate to subfalcate, sometimes falcate, 5.5–18.5 cm long, 0.9–3.5 cm wide, glabrous, dull grey-green; longitudinal nerves numerous and parallel, slightly raised and normally flat-topped (when dry), 4–6 (–7) per mm; pulvinus 3–4 (–4.5) mm long. Inflorescences simple, 1–4 (–5) per axil; peduncles 2–5 mm long, glabrous; spikes 1–4 cm long, very pale yellow (almost cream) to pale yellow. Flowers 5-merous; calyx gamosepalous, shallowly dissected, glabrous; ovary densely hairy on upper half. Pods oblong to narrowly oblong, flat or 1–3 times spirally twisted, 2–10 (–12.5) cm long, 1.4–2.2 (–3.2) cm wide, dehiscing along ventral suture, woody, resinous, glabrous, nerves +/-oblique and not or scarcely raised. Seeds transverse to oblique, usually irregularly-shaped, often twisted, 4–7 mm long, 3–4 mm wide, glossy, black; funicle/aril with 1–3 folds, 4–6 mm long (unextended), creamy, ageing pale yellow.
Distributed across northern Australia from the Kimberley region in W.A. to the Gulf of Carpentaria in N.T. and Qld. It occurs on a number of continental islands within this range, e.g. Lacrosse and Sir Graham Moore Islands in W.A., Bathurst, Goulburn, Melville, Elcho, Wessels, Groote Eylandt and Vanderlin Islands in N.T. and Mornington, Sweers, Andrew and Bentinck Islands in the Gulf of Carpentaria. Acacia lamprocarpa grows in a wide range of habitats including margins of watercourses, coastal sand dune systems (including shell banks), sandstone plateaus and on sandy plains.
Acacia lamprocarpa is a member of the ‘ A. aulacocarpa group’ and until recently was regarded as conspecific with A. aulacocarpa . Based on its ventral mode of pod dehiscence, A. lamprocarpa is most closely related to A. crassicarpa , A. midgleyi and the New Guinea endemic, A. peregrina . Acacia lamprocarpa differs from these, and all other taxa in the A. aulacocarpa group, by its thick, yellow-brown, papery-flaky bark (which is most evident on young and maturing trees); it is also the only taxon in the group that extends westwards to N.T. and W.A. Acacia midgleyi is further distinguished by its pale green phyllodes, longer spikes, crustose pods and longer funicle/aril which is much-folded below the seed. Acacia crassicarpa is further distinguished by its longer pulvinus and funicle/aril, and its lanceolate-falcate phyllodes. Dried specimens of A. lamprocarpa are sometimes difficult to distinguish from A. disparrima . Flowering specimens of A. lamprocarpa can be difficult to distinguish from glabrous forms of A. difficilis but the hairy calyx found in the latter serves to distinguish it. A revision of the ‘ A. aulacocarpa group’ is presented in M.W.McDonald & B.R.Maslin, Austral. Syst. Bot. 13(1): 21–78 (2000).
A putative hybrid between A. lamprocarpa and A. auriculiformis occurs at Holmes Jungle, N.T.
Type of accepted name
Type citation : ‘Port Darwin, Bleeser no. 456’; holo : not seen, presumably originally at B but destroyed; iso : Darwin, Northern Territory, A.C.A.Bleeser 456 (MEL - labelled, presumably in error, Nov. 1929; NSW - labelled Jan 1927).
C.R.Dunlop et al ., Flora of the Darwin Region 2: 7, fig. 2 (1995), as A. aulacocarpa ; L.A.J.Thomson, Acacia aulacocarpa , A. cincinnata , A. crassicarpa and A. wetarensis an Annotated Bibliography (CSIRO: Melbourne.), p. 9, fig. 1A (1994), and B.R.Maslin & M.W.McDonald, A Key to useful Australian Acacias for the Seasonally Dry Tropics (CSIRO: Melbourne.), p. 19 (1996), as A. aulacocarpa subsp. A; M.W.McDonald & B.R.Maslin, A ustral. Syst. Bot . 13(1): 58, fig. 16 & 59, 17 (2000).
W.A.: Site 1, 16 km W of Mount Anderson, K.F.Kenneally 10392 & B.P.M.Hyland (BRI, NSW, PERTH); The Bastion (E side c. 1 km by road below summit), Wyndham, B.R.Maslin 7190 (PERTH); Sir Graham Moore Island, P.G.Wilson 11165 (PERTH). N.T.: Groote Eylandt, I.D.Cowie 1995 (DNA); Cape Shield, C.Dunlop 9495 & I.Cowie (DNA, PERTH); Stuart Highway, 2 km north of Adelaide River, J.R.Macononchie 558 (DNA); 9.3 km S of Nhulunbuy, M.W.McDonald 469 (PERTH); 55 miles [88 km] of Carlton Hill Station , R.A.Perry 2989 & M.Lazarides (PERTH). Qld: 77 km north of Escott homestead by track towards Point Parker, C.Dalliston 287 (BRI); Mornington Island, 29 May 1963, N.B.Tindale s.n. (AD, BRI); South Wellesley Island group, Gulf of Carpentaria, Minakuri, south-west of Bentinck Island, June 1963 , N.B.Tindale s.n.(BRI); 94.2 km west of Burketown, T.K.Vercoe 203 (BRI).
This species was treated as a synonym of A. aulacocarpa in Fl. Australia treatment of Acacia ; the above account is based on the treatment provided by M.W.McDonald & B.R.Maslin (2000), Austral. Syst. Bot . 13: 56–61.