Sonchus asper
(L.) Hill Rough Sow-thistleAnnuals, 20–150(–200) cm high; basal leaf rosette variably developed. Leaves usually lanceolate to oblanceolate in outline, toothed or pinnatifid to pinnatisect, variably lobed, herbaceous to coriaceous, glabrous, often glaucous, apex acute, margins undulate, toothed and pungently spiny; basal leaves sometimes rosetted, 4–25 cm long, 2–7 cm wide, lacking auricles; cauline leaves 6–30 cm long, 2–7 cm wide, with rounded appressed auricles. Peduncles sparsely glandular-hairy; involucre 10–13 mm long; bracts glabrous or with glandular hairs along midline; ligules 4–5 mm long, shorter than corolla-tube. Cypselas elliptic, 2–3 mm long, compressed, 3-ribbed on each face, margins winged, smooth to scabrous on ribs and wings; pappus 7–9 mm long, more or less caducous. Flowers all year, mostly spring–autumn.
LoM, MuM, Wim, GleP, Brid, VVP, VRiv, MSB, RobP, MuF, GipP, OtP, WaP, Gold, CVU, GGr, DunT, NIS, EGL, EGU, WPro, HSF, HNF, OtR, Strz, MonT, HFE, VAlp. Also WA, SA, Qld, Tas. Europe, widely naturalised. Widespread though much of Victoria. A reasonably common weed of usually moist sites both disturbed and relatively intact.
Highly variable in degree of development of basal rosette, leaf dissection and stiffness, glaucescence and prickliness.
More robust plants with well-developed basal rosettes and more dissected and glaucous leaves have been referred to S. asper subsp. glaucescens (Jord.) Ball, but that name is more strictly applied to biennial plants with denser, recurved spines on the cypselas, traits not observed in Australian plants.
Jeanes, J.A. (1999). Asteraceae. In: Walsh, N.G.; Entwisle, T.J., Flora of Victoria Vol. 4, Cornaceae to Asteraceae, pp. 652–666. Inkata Press, Melbourne.