Acacia desertorum Maiden & Blakely, J. Roy. Soc. W. Australia 13: 24; pl. 17, figs 1- 7 (1928)
Shrub 0.6- 2 m high, rarely tree to 4 m high. Branchlets sericeous between the glabrous, resinous ribs. Phyllodes ascending, straight to shallowly incurved, terete to rhombic-terete, (5- ) 5- 13 (- 15) cm long, 1- 1.5 mm diam., coarsely pungent, rigid, grey-green, glabrous or appressed hairy in shallow grooves between nerves, with 8 or 16 closely parallel, flat-topped or slightly rounded, rather broad nerves. Inflorescences simple, 1 or 2 per axil; peduncles 3- 8 mm long, glabrous or sparsely sericeous and sometimes with red, resin-hairs intermixed; heads globular to widely ellipsoid or obloid, 7- 9 mm long, 6- 8 mm diam., subdensely flowered, bright golden. Flowers 5-merous; sepals 3/4-united, 1/4- 1/2 length of petals. Pods linear, straight to slightly curved, quadrangular in section with wide margins, to 8.5 cm long, 1.5- 2 mm wide, thinly coriaceous, minutely sericeous except margins glabrous. Seeds longitudinal, linear, 4- 4.5 mm long, shiny, mottled light brown; funicle/aril compressed-conical, seed-length.
Disjunct, occurring in the Southern Cross and Coolgardie areas and in the Great Victoria Desert, southern inland W.A.
A member of the ‘ A. heteroneura group’, fide R.S.Cowan & B.R.Maslin, Nuytsia 10: 29 (1995). The species is very close to A. heteroneura and the chief difference separating them is the form of the phyllodes which in A. heteroneura are rhombic to compressed-rhombic or flat, infrequently terete (i.e. the phyllodes are generally more angular in A. heteroneura than in A. desertorum ). Superficially resembling the closely related A. cylindrica .
Comprises two allopatric varieties and future studies may indicate the need to treat these as separate species and/or to recognise more entities within this broadly circumscribed species, fide R.S.Cowan & B.R.Maslin, loc. cit.
Phyllodes with 8 broad nerves of equal width
var. desertorum
Phyllodes with 16 nerves of unequal widths
var. nudipes
Acacia desertorum Maiden & Blakely var. desertorum
Phyllodes 8-nerved (the nerves equal width), appressed-hairy in the shallow, discrete grooves between the nerves. Peduncles commonly 2 per axil, substout or rather slender, 0.4- 0.6 mm diam., smooth or longitudinally ridged, resinous or not, glabrous to subdensely sericeous and with or without varying intermixture of red, resin-hairs. Sepals c. 0.5- 0.8 mm long, 1/4- 2/5 length of petals.
Discontinuous, occurring near Coolgardie, Adalong Stn (c. 150 km N of Coolgardie) and in the Great Victoria Desert from Mt Luck E to Plumridge Lakes, W.A. Grows in yellow sand and red loamy sand, in scrub and tall shrubland, or (desert populations) in red sand in open mallee over Triodia sp. (Spinifex).
As discussed by R.S.Cowan & B.R.Maslin, Nuytsia 10: 33 (1995), there appears to be two distinct entities included within var. desertorum as currently defined: specimens from the Great Victoria Desert have peduncles similar to those of var. nudipes whereas the peduncles on plants occurring around Coolgardie are rather slender (0.4- 0.5 mm diam.), resinous, smooth or very obscurely longitudinally ridged and glabrous to sparsely sericeous with varying intermixture of red, resin-hairs. There are also slight flower differences between the two entities.
Some specimens from the Victoria Spring Nature Reserve (south-west extremity of the Great Victoria Desert) appear as though they may combine characters of A. desertorum var. desertorum and A. heteroneura var. jutsonii .
Type of accepted name
Victoria Desert, Elder Exploring Expedition, Camp 54 [29S, 125E], W.A., 17 Sept. 1891, R.Helms 14 ; holo: NSW; iso: K, MEL, PERTH (Fragments ex ?K).
Illustration
J.H.Maiden & W.F.Blakely, J. Roy. Soc. W. Australia 13: pl. 17, figs 1- 7 (1928).
Representative collections
W.A.: Doney Lagoon, Adalong Stn, R.J.Cranfield 7584 (MEL, PERTH); 19 km W of Coolgardie on Great Eastern Hwy, B.R.Maslin 4822 (CANB, K, MEL, PERTH); Great Victoria Desert, c. 60 km NW of Plumridge Lakes, B.R. Maslin 5717 (MO, NSW, PERTH).
Acacia desertorum var. nudipes R.S.Cowan & Maslin, Nuytsia 10: 34 (1995)
Phyllodes 16-nerved but often only 8 nerves visible when young (the nerves of unequal width), glabrous or appressed-hairy between nerves. Peduncles normally solitary, substout, 0.5- 0.8 mm diam., longitudinally ridged when dry, not resinous, glabrous or subglabrous (no resin hairs). Sepals 1- 1.1 mm long, c. 1/2 length of petals.
Restricted to areas between Southern Cross and Boorabbin (c. 90 km E of Southern Cross), W.A. Grows on yellow sandplains and lateritic gravel, in heath and tall open shrubland.
Type of accepted name
9.1 miles [14.6 km] W of Yellowdine towards Southern Cross, W.A., 18 Sept. 1982, R.J.Cumming 2470 ; holo: PERTH; iso: MELU.
Representative collections
W.A.: Koorarawalyee, J.S.Beard 6238 (PERTH); 12.6 km E of Southern Cross on Great Eastern Hwy, B.R. Maslin 2388 (PERTH); 10 km SE of Ghooli, c. 19 km SE of Southern Cross, K.Newbey 6022 (PERTH).
(RSC & 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.
