Intricate, usually erect, clonal shrub to 50 cm, grey-green, occasionally rusty-green, densely pubescent with stellate hairs; prickles to 10 mm long, common on most parts.

Leaves ovate-lanceolate to oblong; lamina 3–6 cm long, 1.5–3 cm wide, sometimes larger, slightly to distinctly discolorous, shallowly to deeply lobed; petiole 5–15 mm long.  

Inflorescence 3–10–flowered; peduncle 5–10 mm long, sometimes to 30 mm; rachis to 5 cm long; pedicels 5–10 mm long. Calyx 8–10 mm long; lobes narrowly triangular with linear apices, 6–7 mm long, elongated slightly in fruit. Corolla shallowly campanulate-rotate, 25–30 mm diam., purple. Anthers 4–6 mm long.  

Berry globular or depressed globular, 8–10 mm diam., sometimes to 15 mm, yellow, drying pale brown. Seeds 1–1.5 mm long, light brown or grey-brown, finally hard and bony. n=12, 24.

A DELTA-generated description with further inforamtion can be seen at http://delta-intkey.com/solanum/www/petrophi.htm

Associated with ranges in arid areas, occurring in the Coolgardie area of W.A., the Macdonnell, Musgrave and Everard Ranges of Central Australia, the Gawler and Flinders Ranges of S.A., and the Barrier Range of N.S.W.  

Grows in rocky habitats or close to the base of ranges.

Suspected of poisoning stock in N.S.W. and W.A. 

Gawler Ranges populations, as shown in one of the attached images, may have flowers which are less rotate than usual.

There is contrasting information about the fire response of this species on the North Australian Land Manager site. One record indicates that it is killed by fire and hence may be eliminated by frequesnt fires whereas another indicates that it is capable of resprouting - see www.landmanager.org.au/view/317664/fire_responses_of_isolanum_petrophilum/i.html