Family

Fabaceae

Distribution

Seemingly confined to the Gulf country of north-eastern N.T. and adjacent north-western Qld. The two specimens from W.A. that were cited by A.S.George, Fl. Australia 11B: 399 (2001), under A. asperulacea appear to represent an undescribed species related to A. orthotricha.

Description

Shrub to 1 m high. Branchlets glabrous, pubescent or pilose with spreading to ±retrorse lax hairs, ±viscid; internodes often to 3 times as long as phyllodes. Stipules 1–2 mm long. Phyllodes (8–) 10–14 per whorl, ascending, slightly flattened, slender, straight to shallowly incurved or shallowly sigmoid, normally recurved to some degree at apices, 5–8 (–14) mm long, glabrous or pilose to scabrid, with impressed nerve on upper surface; mucro 0.1–0.3 mm long. Peduncles mostly 10–25 mm long, glabrous or pilose. Heads 15–30-flowered. Flowers 5- or 6-merous; calyx 0.6–0.9 mm long, ribbed, glabrous (or lobes ciliate); calyx lobes incurved, linear to narrowly triangular, 0.2–0.4 mm long, thick; corolla lobes striate, sparsely hispid. Pods sessile, linear, 30–35 mm long, 4.5–6.5 mm wide, glabrous; margins slightly thickened. Seeds (not seen mature) longitudinally oblique, c. 3 mm long.

Specimens

N.T.: 45 km S of McArthur River Stn, R.A.Perry 1689 (BRI, CANB, MEL). Qld: Settlement Ck, Burke District, L.J.Brass 151 (BRI, CANB, MEL); 22 km SW of Kamilaroi Stn, M.Lazarides 3972 (BRI, CANB, DNA, MEL, PERTH).

Notes

Until the types are found, Domin’s f. denudata and f. hirsutiuscula cannot be applied with certainty.

Acacia asperulacea was based on two collections, F.Mueller 1 (‘Arnhems Land’) and F.Mueller 73 p.p. (‘Upper Victoria R.’). While it is likely that these collections represent different taxa, namely, A. asperulacea as defined above and A. repens, it is difficult to be certain because the critical pod character that discriminates these species cannot be determined from the type specimens at MEL. Pods are clearly stipitate in A. repens. The N.Byrnes 764 specimen from Jasper Gorge, NT, cited by L.Pedley, Contr. Qd Herb 11: 9 (1972), under A. asperulacea has the distinctly stipitate pods and is therefore referred to A. repens.

Also related to A. perryi but typically less hairy with less flattened phyllodes, and less prominent stipules and bracteoles (less than 2 mm long). It lacks the long mucro of A. lycopodiifolia and its phyllodes are longer and commonly recurved at apices.

FOA Reference

Data derived from Flora of Australia Volumes 11A (2001), 11B (2001) and 12 (1998), products of ABRS, ©Commonwealth of Australia

Author

Minor edits by J.Reid

A.S.George