S. Columbaria: stems 1-2 feet high, glabrous or hoary; leaves pinnate, with an ovate or oblong terminal segment, and several smaller ones, the stem-leaves few, with linear segments, entire or pinnatifid; flower-heads pale purplish-blue, the outer florets larger and more oblique; involucres short; involucel with a scarious, cup-shaped border, in the centre of which appears the summit of the fruit crowned by the five bristles of the calyx. - Pastures and waste places. Fl. June to August.
** Florets four-lobed.
S. arvensis: stems erect, hairy near the base, 1-3 feet high; leaves variable, the radical ones lanceolate, stalked, the upper ones broader at the base, sessile, all coarsely toothed or slightly lobed, or deeply-cut or pinnate; flower-heads large, pale lilac-purple, on long peduncles, the outer florets much larger and more oblique than the central ones; involucre short; fruit crowned by the 8-10 radiating bristles of the calyx. - Pastures and cornfields. Fl. July, August.