Annual herb 20–150 cm tall, erect; stems green striate with purple, densely to sparsely pubescent or setulose. Leaves sessile, obovate, oblanceolate, elliptic or lanceolate, rarely ovate, unlobed or (especially the upper) lyrato-pinnately or pinnately 2–8-lobed, 1.2–20 cm long, 0.5–7.5 cm wide, cuneate or attenuate into an exauriculate petioloid base or (especially the upper) sessile, margins remotely sinuate-denticulate to coarsely sinuate-serrate, apex rounded to obtuse or acute, scattered-pubescent at least on veins beneath. Capitula 1–8, long-stalked, usually at first nodding then ± erect, but sometimes erect throughout, discoid; stalks of the individual capitula ± pubescent and purplish-tinged; involucre cylindrical, 8–13 mm long, 2.5–8 mm in diameter; bract of calyculus 5–23, purplish or dark green with purple tips, lanceolate or narrowly lanceolate, 3–6(–8) mm long, glabrous or ciliate; phyllaries 13–25, commonly 21 or 13, pale green to green, often tinged purple especially towards the apex and purple-tipped, 7.5–12 mm long, glabrous or sparsely shortly pubescent. Disc florets blue, purple or mauve, less often pink or red; corolla 6.2–10.5 mm long, tube glabrous, gradually expanded in upper third, lobes 0.4–1.5 mm long. Achenes 2–2.5 mm long, ribbed, hairy or shortly so in the grooves; pappus 7–12 mm long.
