Acacia disticha Maslin, Nuytsia 10: 89 (1995)
Glabrous shrub c.1 m high, to 2 m in sheltered situations. Branchlets roughened by raised leaf bases where phyllodes have fallen. Phyllodes distichous on flattened branchlet extremities, spiral with age where branchlets are terete, elliptic, variable in size, 15–43 mm long, 4–22 mm wide, l:w = 2- 4, obtuse, thin, green, imperfectly 2-nerved; lateral nerves absent or few and obscure; gland not prominent, 2–5 mm above pulvinus. Inflorescences simple or 2-headed racemes; raceme axes normally c. 4 mm long; peduncles 7–11 mm long; heads globular, loosely 6- or 7-flowered, cream. Flowers 4-merous; sepals c. 1/4 length of corolla, united into a truncate to sinuolately lobed calyx. Pods spreading to subretrorse by a strongly recurved stipe, narrowly oblong, to 4 cm long, 5 mm wide, crustaceous to subwoody; margins thick. Seeds (slightly immature) longitudinal, oblong, 4 mm long, slightly shiny, brown; aril terminal.
An uncommon species principally confined to the Fitzgerald R. Natl Park (SW of Ravensthorpe) in the vicinity of Thumb Peak and Mid Mt Barren, also Corackerup Ck, c. 100 km to the WSW, and in the Ravensthorpe Ra., c. 40 km to the NE, south-western W.A.. Grows along watercourses in loamy clay or sand and silt, normally in tall shrubland or Eucalyptus eremophila closed scrub where it dominates the low shrub stratum.
Phyllodes vary considerably in size, even on a single specimen. On upper branchlets they are 15–30 mm long and 4–15 mm wide, whereas lower down they may reach 45 mm long and 25 mm wide.
A member or the ‘ A. myrtifolia group’ and perhaps most closely related to A. pygmaea . Sometimes sympatric with A. myrtifolia which can be distinguished by its prominently ribbed, angular branchlets, non-distichous, thicker, prominently 1-nerved phyllodes with a more prominent gland, and longer pods with clearly undulate margins.
Type of accepted name
N end of Middle Mt Barren, Fitzgerald R. Natl Park, W.A., 20 Dec. 1970, A.S.George 10588A ; holo: PERTH; iso: CANB, K, NY.
Representative collections
W.A.: Corackerup Ck, Feb. 1934, E.T.Bailey s.n. (PERTH); c. halfway between Kundip Mine and Elverton Mine, Ravensthorpe Ra., G.Craig 2011 (PERTH); Thumb Peak, Fitzgerald R. Natl Park, K.Newbey 3419 (BRI, CANB, K, MEL, NY, PERTH); 1 km N of Twin Bay, in gully leading from SW slopes of Thumb Peak, Fitzgerald R. Natl Park, B.R.Maslin 5553 (CANB, K, MO, PERTH).
(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.
