Acacia heteroneura Benth., Linnaea 26: 624 (1855)
Shrub normally 1- 2.5 m high. Branchlets sericeous between the glabrous, resinous ribs. Phyllodes linear, rhombic to compressed-rhombic or flat, infrequently terete, 3- 13 cm long, 0.7- 3.5 mm wide, acute and mostly innocuous or coarsely pungent, rigid, (silvery green) green to grey-green or glaucous, sericeous between nerves, the nerves often resinous, those on the angles (of rhombic phyllodes) or the central nerve and margins (of flat phyllodes) prominent and clearly wider than the intervening secondary nerves. Inflorescences simple, 1 or 2 per axil; peduncles glabrous to sericeous; heads globular to broadly ellipsoid or obloid, 5- 9 mm long, 5- 8 mm diam., subdensely flowered, bright golden. Flowers 5-merous; sepals at least 3/4-united, 1/4- 1/3 petal length. Pods normally erect, linear, straight, quadrangular-terete, to 10.5 cm long, 1.5- 3 mm wide, crustaceous to woody-crustaceous, minutely sericeous except margins glabrous. Seeds longitudinal, narrow-oblong to narrowly elliptic, 3- 5.5 mm long, subnitid, variously obscurely mottled; aril 1/3 to as long as seed.
Widespread but scattered from Wubin (c. 20 km due N of Dalwallinu) NE to Wiluna and SE to Lake King (c. 115 km due E of Lake Grace) and Queen Victoria Spring Nature Reserve area (c. 200 km due ENE of Kalgoorlie), W.A.
Acacia heteroneura together with A. cylindrica , A. desertorum and A. epedunculata constitute the ‘A. heteroneura group’; see R.S.Cowan and B.R.Maslin, Nuytsia 10: 29 (1995), for discussion. Acacia heteroneura appears most closely related to A. desertorum ; it also has some resemblance to A. anfractuosa (sect. Plurinerves ).
The differences between the four varieties recognised for A. heteroneura are found principally in their phyllode morphology.
Key
1 Phyllodes flat to compressed-rhombic, commonly 5- 7 cm x 2- 4 mm
var. heteroneura
1: Phyllodes angular-rhombic to terete
2 Phyllodes 3- 6 cm x 0.7- 1 mm, somewhat pungent
var. petila
2: Phyllodes some or all longer and/or wider than above
3 Phyllodes 7- 13 cm x 1- 1.5 mm; flower-heads ellipsoid to obloid
var. prolixa
3: Phyllodes 4- 7 cm x 1- 1.7 mm or, if longer, then flower-heads globular
var. jutsonii
Acacia heteroneura Benth. var. heteroneura
Shrub 0.15- 3.5 m high. Phyllodes compressed-rhombic to flat, 5- 7 (- 11) cm long, 2- 4 mm wide, sericeous between the 3- 7 nerves on either side of a prominent central nerve, the hairs sparse or sometimes absent with age. Peduncles 4- 6 mm long; flower-heads globular, 5- 6 mm diam. Pods erect, to 5.5 cm long, 2 mm wide, crustaceous; margins narrow. Seeds 3- 3.5 mm long, mottled light and darker brown.
Most common from Tammin SE to Bruce Rock and E to Westonia (c. 45 km due ENE of Merredin), with a single collection from near Anketell (c. 350 km due N of Westonia), south-western W.A. Grows in yellow sand and sandy loam (and red sand in the N), in mixed shrubland and scrub.
Somewhat arbitrarily separated from var. jutsonii which has narrower, clearly rhombic (in section) phyllodes. Variety jutsonii occurs within the geographic range of var. heteroneura but it is not known if the two are ever sympatric. Also related to A. ampliata .
Type of accepted name
South-west W.A., 1849, J.Drummond 2: 138 ; holo: K; iso: MEL, PERTH (Fragment ex K).
Representative collections
W.A.: 6.4 km E of Anketell, J.W.Green 1644 (PERTH); c. 29 km due NW of Bruce Rock, B.R.Maslin 1794 (AD, CANB, K, PERTH).
Acacia heteroneura var. jutsonii (Maiden) R.S.Cowan & Maslin, Nuytsia 10: 37 (1995)
Dense shrub 0.5- 3 m high. Phyllodes angular-rhombic in section, mostly 4- 7 (- 10) cm long, 1- 1.7 mm wide, sericeous generally or only between nerves (oldest phyllodes sometimes glabrous), the nerve at apex of each angle prominent and clearly wider than the 3 intervening secondary nerves. Peduncles 3- 6 mm long, sericeous with red resin-hairs variously intermixed; flower-heads globular to widely ellipsoid, 5- 8 mm long, 5- 7 mm diam. Pods to 8.5 cm long, 2- 2.5 mm wide; margins narrower than valve width. Seeds narrowly oblong to narrowly elliptic, 3.5- 4.5 mm long, grey-brown or yellow-brown with darker brown mottlings.
Widespread but disjunct, occurring from Kalannie (c. 45 km due E of Dalwallinu) SE to Frank Hann Natl Park (located 30- 110 km ENE of Lake King) and further inland at Comet Vale (c. 100 km due NNW of Kalgoorlie), Bandya Stn (c. 120 km due N of Laverton) and Queen Victoria Springs Nature Reserve area, southern W.A. Western populations grow in yellow sand and gravelly sand, in scrub, heath, open shrubland and woodland; eastern populations grow in red and yellow sand, on plains and dunes, in open Mallee ( Eucalyptus sp.) and Spinifex ( Triodia sp.) communities.
A number of collections from Queen Victoria Spring Nature Reserve appear to combine characters of A. heteroneura var. jutsonii and A. desertorum var. desertorum , e.g. A.S.Weston 14880 (PERTH, Z). Further studies of these populations are needed in order to ascertain their taxonomic status.
Type of accepted name
Comet Vale, W.A., Dec. 1916, J.T.Jutson 49 ; lecto: NSW, fide R.S.Cowan & B.R.Maslin, loc. cit. ; isolecto: NSW, PERTH (Fragment ex NSW); Comet Vale, W.A., J.T.Jutson 160 ; paralecto: NSW.
Synonymy
Acacia jutsonii Maiden (as ‘jutsoni’), J. & Proc. Roy. Soc. New South Wales 51: 262 (1917). Type: as for accepted name.
Representative collections
W.A.: 4.8 km from Hines Hill towards Nungarin, B.R.Maslin 2341 (AD, BRI, CANB, DNA, HO, K, MEL, NSW, PERTH); Queen Victoria Spring Nature Reserve, D.J.Pearson 121 (PERTH); Frank Hann Natl Park, R.D.Royce 10210 (B, PERTH); 30 km NE of Bandya HS, c. 120 km N of Laverton, P.G.Wilson 7352 (BRI, PERTH).
Acacia heteroneura var. petila R.S.Cowan & Maslin, Nuytsia 10: 38 (1995)
Phyllodes terete to rhombic-terete in section, sometimes angular-rhombic, 3- 6 cm long, 0.7- 1 mm diam., somewhat pungent, sericeous between the nerves or glabrous (young phyllodes with minute, red resin-hairs especially on the main nerves), the nerve at apex of each (normally slight) angle slightly or obviously wider than the 3 intervening nerves. Peduncles 2- 6 mm long, densely sericeous with varying proportions of red resin-hairs intermixed; flower-heads globular, 5- 6 mm diam., golden. Pods to 8 cm long, 1.5- 2 mm wide, 2- 2.5 mm thick; margins about as broad as valve width. Seeds 3.5- 4 mm long, yellowish brown with sparse darker brown mottlings.
Restricted from Miling (c. 30 km due SW of Dalwallinu) SE to Trayning (c. 60 km due NW of Merredin), with a variant from Morawa and near Wubin, south-western W.A. Grows in yellow sand and gravelly sand, in scrub and shrubland.
Plants from the Wubin area have slightly coarser phyllodes than those elsewhere, i.e. to 1.2 mm diam. (e.g. E.M.Canning WA/68 2920 ).
Variety petila is recognised by its short, non-flat, somewhat pungent phyllodes. The position of this taxon within the ‘Acacia heteroneura Group’ needs to be reassessed, fide R.S.Cowan & B.R.Maslin, Nuytsia 10: 39 (1995).
Type of accepted name
5 km SW of Kulja towards Burakin, W.A., 9 Jan. 1979, B.R.Maslin 4442 ; holo: PERTH; iso: CANB, G, K, MEL, NY.
Representative collections
W.A.: between Maya and Latham, T.E.H.Aplin 427 (PERTH); between Pithara and Miling, W.E.Blackall 2889 (PERTH); 8.5 km from Wubin towards Wongan Hills, E.M.Canning WA/68 2920 (PERTH: variant); c. 13 km E of Wyalkatchem towards Trayning, F.Lullfitz L3058 (PERTH).
Acacia heteroneura var. prolixa R.S.Cowan & Maslin, Nuytsia 10: 40 (1995)
Phyllodes angular-rhombic in section, sometimes flat, 7- 13 cm long, 1- 1.5 mm wide, sericeous generally (especially when young) or only between nerves, the nerve at apex of each angle clearly wider than the 3 intervening fine secondary nerves. Peduncles commonly solitary, 5- 8 mm long, sericeous with few, obscure, light brown resin-hairs intermixed; flower-heads widely ellipsoid to obloid, 8- 9 mm long, 7- 8 mm diam. Pods (few seen) to 10.5 cm long, 2.5 mm wide, tapered to stipe; margins about equalling valve width. Seeds (few seen) 4.5- 5.5 mm long, tan mottled yellow.
Scattered from Wubin E to near Wiluna and Laverton, southern W.A. Northern populations grow in red sand in shrubland with Spinifex ( Triodia sp.), and southern populations grow in sand over laterite in shrubland.
Most closely related to var. jutsonii which normally has shorter phyllodes and globular to widely ellipsoid flower-heads; variety prolixa occurs to the north of the geographic range of var. jutsonii .
Type of accepted name
17 km due NE of Wiluna, 8.5 km N of ‘Gunbarrel Hwy’ on road to Jundee Stn, W.A., 4 Sept. 1984, B.R.Maslin 5591 ; holo: PERTH; iso: BRI, CANB, G, K, MEL, NSW, NY.
Representative collections
W.A.: 35.4 km NE of Laverton, A.S.George 2821 (PERTH); 0.3 km N of Wubin, N.Hoyle 338 (PERTH); 106 km N of Sandstone towards Wiluna, R.D.Royce 10386 (CANB, K, PERTH).
(RSC)
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.
