Acacia dilloniorum Maslin

Intricately branched shrub (0.3–) 0.5–1.8 m high. Branches glabrous, dividing into numerous, short, straight, rigid, divaricate, coarsely pungent branchlets. Phyllodes crowded, normally single at nodes but often appearing sub-fasciculate on short shoots, elliptic, oblong-elliptic, obovate or oblanceolate, (5–) 7–12 (–15) mm long, (2–) 3–5 (–7) mm wide, apices asymmetrically narrowed to a slender, pungent cusp, glabrous; midrib ±prominent, lateral veins anastomosing near phyllode margins; pulvinus distinct and 0.5–1 mm long; gland basal. Inflorescences simple; peduncles 8–20 mm long, glabrous; heads globular to obloid, yellow. Flowers 5-merous; sepals united. Pods narrowly oblong, 25–55 mm long, 4.5–5.5 mm wide, curved (sometimes into an open circle), coriaceous, reddish brown, very obscurely reticulately veined, glabrous. Seeds longitudinal, obloid but noticeably constricted at the hilar end, 3.5–4 mm long; aril extending ⅓–½ down one side of the seed.

Grows in red clay-loam or red-brown silty clay-loam on the middle and upper slopes and crests of low ranges mostly associated with outcropping basalt, in tall open shrubland.