Acacia ancistrocarpa x trachycarpa
More or less obconic shrubs to 3 m tall, with a rather spreading and untidy aspect, single-stemmed or sparingly branched at ground level. Bark grey, exfoliating in a "Minni Ritchi" fashion (i.e. shedding in narrow strips which curl retrorsely from each end) at extreme base of main trunk revealing a reddish brown underlayer, soon becoming smooth. Branchlets glabrous. Stipules triangular to deltate, 0.5–1 mm long, dark brown. Phyllodes broad-linear to very narrow elliptic, 9–12 cm long, 4–10 mm wide, normally slightly curved, not rigid, somewhat shiny (at least when young), glabrous, medium pure green, upper margin slightly thickened, apices acute and innocuous to coarsely pungent; nerves numerous and parallel, sometimes sparingly anastomosing, 0.2–0.3 mm apart, the central nerve and one on either side of it more evident than the rest. Spikes 20–25 mm long; peduncles 6–12 mm long, glabrous. Flowers 5-merous; calyx dissected for c. 1/2–3/4 its length, short-villous. Pods and seeds not seen.
Known from a few scattered localities in the Pilbara region, north-west W.A.
Judging from field observations and morphological criteria this taxon appears to be a hybrid between A. ancistrocarpa and A. trachycarpa . Both putative parents have been observed in at least one population containing a few hybrid plants; no apparent back-crossing was observed here. For further information see Maslin (1983), Nuytsia 4(3): 405–407.
Illustration
B.R.Maslin, op. cit. 406, fig. 13.
Representative collections
W.A.: Nullagine road south of Mount Edgar Station, N.T.Burbidge 1134 (BRI, PERTH); 6 mi [10 km] N of fortescue River crossing on North West Coastal Hwy, B.R.Maslin 2758 (CANB, K, PERTH).
(BRM)
This hybrid is noted in the Fl. Australia treatment of Acacia under both A. ancistrocarpa and A. trachycarpa . The above description is abstracted from the treatment provided by B.R.Maslin, Nuytsia 4(3): 405–407 (1983).
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.
