Acacia atrox (a tall shrub) - endangered species listing

The Scientific Committee, established by the Threatened Species Conservation Act, has made a Final Determination to list Acacia atrox Kodela ms, a tall shrub, as an ENDANGERED SPECIES on Part 1 of Schedule 1 of the Act. Listing is provided for by Part 2 of the Act.

Note:  This Determination has been superseded by the 2023 Final Determination for Acacia atrox Kodela.

NSW Scientific Committee - final determination

The Scientific Committee has found that:

1. Acacia atrox Kodela ms previously known as Acacia sp. 'Myall Creek' (Miller s.n. 25 May 2000), is a newly discovered species, recognised by taxonomists at the NSW National Herbarium.

2. Acacia atrox Kodela ms is a dense, much branched shrub 0.5-1.5 (-2) m high (potentially becoming taller since there is an older plant to 4 m high); main stem less than 10 cm d.b.h, sometimes twisted; spreading by suckering. Bark grey-brown, becoming dark grey and vertically fissured with age. Branchlets terete, pale green and slightly pruinose to pale yellowish green when dry, occasionally with a pinkish tinge on young stems, sometimes becoming encrusted with a brownish to blackish material with age, glabrous, with very low rounded ridges; axillary branchlets and phyllode clusters borne in a pair of partly overlapping, caducous bracts (which usually leave fine scars on the stem when shed). Phyllodes sessile, patent to slightly inclined, very narrowly linear, more or less straight, more or less quadrangular in section (to more or less terete), with a yellow vein at each angle and a less prominent vein in between these (more or less 8-veined altogether, however, the intermediate veins are often incomplete not reaching the apex, obscure, wrinkle-like or not apparent), (1.5-) 2-4 (-4.5) cm long, 1-1.2 (-1.3) mm wide, rigid, light green (dry), glabrous, gradually tapered towards a pungent-pointed apex (the fine tip orange-brown and 1.5-3.5 mm long), abruptly broadened or splayed at base 2-5.5 mm wide (leaving an oval-obovate scar on branchlet when lost), with a small orbicular gland on upper vein/margin near or to 3 mm above base and often a second minute gland c. 1/3-2/3 from base; galls with a shape that is hakea fruit-like are commonly formed within some phyllodes. Inflorescences normally paired (often one of the peduncles missing) or sometimes single on a rudimentary raceme axis to 1 mm long in phyllode axils (often appearing simple); peduncles 5-21 mm long, glabrous; bracts one either side at base of the peduncle pair originally enclosing the undeveloped inflorescences, deeply convex, more or less broadly ovate, often with a split or minor lobe/peak about midway below either side of the apex, to 2 mm long, sparsely ciliolate, often caducous; heads globular, c. 17-25-flowered, 5-7 mm diam. (dry), cream-coloured to pale yellow. Bracteoles more or less obovate to broadly spathulate, 0.9-1.1 mm long, ciliolate, the claw also with scattered minute hairs on outer surface especially along midrib. Flowers 5-merous; calyx cupular, 0.8-1.2 mm long, dissected ¼ (-1/3) or less, with minute hyaline-white hairs at base and often scattered on tube or concentrated along ribs, ciliolate along the obtuse to broadly rounded sepal apices; corolla dissected 1/3-1/2 or more, probably splitting with age, glabrous, the petals 1.5-1.9 mm long, acute, often purplish in upper half; ovary glabrous to white-puberulous. Pods not seen, possibly rarely, if ever, produced. Acacia atrox Kodela ms has some affinities with Acacia carneorum that occurs in far western NSW. Unlike Acacia atrox Kodela ms, A. carneorum does not have a splayed phyllode base, has hairy branchlets and phyllodes especially when young and has simple inflorescences of yellow to bright golden-yellow flower-heads.

3. Acacia atrox Kodela ms is known only from a single location South of Delungra, West of Inverell and grows on basalt derived soil.

4. Acacia atrox Kodela ms is not known to occur in any New South Wales National Parks and Wildlife Service conservation reserve.

5. An immediate threat to the survival of Acacia atrox Kodela ms is clearing for pasture improvement. Its very small and localised extent, potential to be grazed, and potential changes in fire regimes leave it threatened by stochastic processes. The risk of extinction is high due to low population numbers.

6. In view of 3, 4 and 5 above the Scientific Committee is of the opinion that Acacia atrox Kodela ms is likely to become extinct in nature in New South Wales unless the circumstances and factors threatening its survival and evolutionary development cease to operate.

Proposed Gazettal date: 13/07/01
Exhibition period: 13/07/01 - 17/08/01
Provisionally listed as an endangered species on 25 August 2000.

Reference:

Kodela, P. G.Acacia atrox (Fabaceae: Mimosoideae), a rare species from the North Western Slopes, New South Wales. Submitted for publication in Telopea, Dec. 2000.