Acacia auricoma Maslin, J. Adelaide Bot. Gard. 2: 303; 304, fig. 2 & 320, fig. 8 (1980)
Alumaru or Nyalpilintji Wattle
Rather straggly shrub 1.5–3 m high. Branchlets terete, minutely stellate-velvety, rarely glabrous. New shoots usually golden-hairy. Stipules 1–1.5 mm long. Phyllodes inequilaterally elliptic, 3–10 cm long, 1.5–4 cm wide, rotund-obtuse, coriaceous, subglaucous, usually minutely stellate-velvety, with 3–5 raised main nerves (some confluent with lower margin for c. 1 cm above pulvinus), prominently reticulate; gland basal, 2–4 additional glands in shallow notches along upper margin. Inflorescences simple but forming terminal ‘false’ racemes by phyllode suppression; peduncles mostly 2 per axil, normally 20–30 mm long and golden stellate-hairy, stout, furrowed; heads globular, 7–8 mm diam., densely 100–135-flowered, golden. Flowers 5-merous, sepals 1/4–1/2-united, the lobes densely golden-puberulous; petals apically golden-puberulous. Pods narrowly oblong, flat, to 8 cm long, 15–25 mm wide, firmly chartaceous to thinly coriaceous, transversely reticulate, stellate-puberulous; margins narrowly winged. Seeds transverse, oblong to elliptic-oblong, 5.5–6.5 mm long, dull, dark brown; aril terminal.
Occurs at Anne Ra., W.A., also E from Bloods Ra. to the Petermann Ra., N.T. Grows in skeletal soil on quartzite scree slopes in open shrubland with spinifex.
Most closely related to A. retivenea , which lacks the golden hairy new shoots, peduncles, bracteoles, sepals and petals normally characteristic of A. auricoma ; furthermore, A. retivenea has larger stipules and branchlets and phyllodes with a crispate-villous or tomentose indumentum, not minutely stellate-velvety as in A. auricoma . Rare glabrous variants occur in both species. Stellate hairs are uncommon in Acacia but they are found also in a few related northern species such as A. flavescens , A. leptoloba and A. sericata , all of which are distinguished by their racemose inflorescences.
One fruiting collection, S.J.Midgley 554 (PERTH), is aberrant in being glabrous throughout but in other respects appears to represent the species.
Type of accepted name
Bloods Ra., N.T., 10 Apr. 1972, J.R.Maconochie 1395 ; holo: PERTH; iso: AD, B, BRI, CANB, DNA, K, MEL, NSW, NT.
Illustrations
B.R.Maslin, op. cit. 304, fig.2.
Representative collections
W.A.: near E end of Anne Ra., A.S.George 12094 (PERTH); N.T.: Shaw R., East Petermann Ra., W.H.Butler 7 (PERTH); Mannanana Ra., Petermann Aboriginal Reserve, T.S.Henshall 2146 (PERTH); Livingstone Pass, Docker R., S.J.Midgley 554 (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.
