Annual herb, from almost acaulescent to 60 cm high; stems erect, hardly branched, striate, glabrous.. Leaves at first forming a rosette, eventually all cauline, somewhat glaucous, sometimes described as slightly succulent, oblanceolate in outline, 2–14 cm long, 0.7–4 cm wide, base auriculate with toothed, rounded auricles, margins dentate, pinnatilobed or pinnatifid with white spinules all along the margins, apex attenuate to acute, glabrous.. Capitula terminal, solitary or paired, on swollen stalks to 26 cm long, these becoming corky at the fruiting stage; involucre 8–18 mm long; phyllaries ovate (outermost) to lanceolate, 5–17 mm long, with broad scarious margins, apiculate, glabrous.. Corolla yellow, sometimes with purple base or the outermost with reddish or purplish tips, tube cylindric, 3.5–8.5 mm long, ligules 5–11 mm long, 0.5–2 mm wide.. Achenes whitish, ellipsoid, 1.5–4 mm long, tuberculate; pappus white, 6–11 mm long.. Fig. 23.
A herb. It can grow each year from seeds or keep growing for a few years.