Acacia dunnii (Maiden) Turrill
WATTLE
Acacias of Australia
Common Name
Dunn’s Wattle, Elephant-ear Wattle
Family
Fabaceae
Distribution
Occurs in north-western Australia lowlands from Walcott Inlet (W.A.) to Victoria R. (N.T.), extending farther inland along the Ord R. valley to Mabel Downs Stn. Also recorded from some islands near the Kimberley coast. Widely cultivated with occasional escapees becoming established in N.T., fide G.J.Leach, Nuytsia 9: 353, 1994.
Description
Pruinose shrub or tree to 6 m high. Branchlets terete, glabrous. Phyllodes inequilaterally elliptic to ovate, shallowly falcate, 12–42 cm long, (4–) 6–17 cm wide, very unequal at base, 2–4-times crenate on upper margin, obtuse, coriaceous, glabrous, with 4 or 5 prominent longitudinal nerves confluent with lower margin at base, closely reticulate between main nerves. Inflorescences in terminal or axillary panicles 11–50 cm long; peduncles 8–20 mm long, single or fascicled, glabrous; heads globular, 6–8 mm diam., 50–85-flowered, golden. Flowers 5-merous; sepals 1/4–1/2-united. Pods narrowly oblong, straight, to 17 cm long, 2–4 cm wide, subwoody, coarsely reticulate. Seeds transverse, broadly elliptic to oblong-elliptic, 9–12 mm long, subnitid, brown with brown-black periphery; aril apical.
Habitat
Grows in gravelly soil, often on rocky slopes.
Specimens
W.A.: New York Jump Ups, J.R.Maconochie 148 (PERTH); Mabel Downs Stn., Winnama Gorge, E.A.Chesterfield 213 (PERTH); West Governors Is., Napier Broome Bay, 19 May 1984, J.H.Willis (PERTH). N.T.: Victoria R., 25 May 1922, E.J.Dunn (K); 22.5 km W of Timber Ck., A.S.George 6531 (PERTH).
Notes
Maiden formally described A. sericata var. dunnii based on material collected by E.J.Dunn who published notes in a paper in 1916 (Proc. Roy. Soc. Victoria 28(2): 228). Our interpretation is that Turrill, by citing Maiden’s name in synonymy, based A. dunnii on Maiden’s varietal name. The material Turrill cited as just having received in 1922, we interpret as additional to that originally used by Maiden. Given this interpretation, the correct author citation is as given above.
Related to A. platycarpa and A. sericata both of which have considerably smaller phyllodes. As W.B.Turrill, Bull. Misc. Inform. 1922: 299 (1922), observed, A. dunnii combines phyllode characters of A. platycarpa with the wingless pods of A. sericata. Also related to A. tolmerensis.
FOA Reference
Data derived from Flora of Australia Volumes 11A (2001), 11B (2001) and 12 (1998), products of ABRS, ©Commonwealth of Australia
Author
R.S.Cowan, B.R.Maslin
Minor edits by J.Rogers
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