Leafless Rock Wattle

Acacia aphylla is widely branched, spiny, glaucous, glabrous shrub that grows to a height of 0.9–3 m (2 ft 11 in – 9 ft 10 in) and has no leaves or phyllodes. The flowers are borne in spherical heads of 20 to 30 on a peduncle 7–10 mm (0.28–0.39 in) wide, and are bright, light golden. Flowering occurs from August to October, and the fruit is a leathery, linear pod 30–90 mm (1.2–3.5 in) long and 3–4 mm (0.12–0.16 in) wide containing seeds that are oblong, 4.0–4.5 mm (0.16–0.18 in) long.

Leafless rock wattle has a restricted range and is only found in two areas in the Darling Range about 60 kilometres (37 mi) apart from each other. The areas are both to the east of Perth with one population being found in Hidden Valley area in the Helena River and the other south of Northam in the Clackline Nature Reserve. The species is commonly found in open forest communities that are dominated by Eucalyptus marginata and Eucalyptus calophylla, or in woodlands where Eucalyptus loxophleba dominates. Species commonly found in the understorey include Grevillea endlicheriana, Hakea petiolaris, and Xanthorrhoea preissii. It is generally associated with areas of laterite and granite outcrops on hillsides, and will grow in rock crevices. It is mostly found to grow in soils that are sandy, loam, clay, or gravel and brown or yellow in colour. Plants are mostly killed by fire but populations will regenerate from the soil seedbank.