General:
Annual or rarely biennial herb from a fibrous root; stems erect, branched, finely-appressed straight-hairy, to moderately stiff long-hairy, sometimes almost glabrous, 30-70 cm tall.
Leaves:
Basal leaves mostly oblanceolate or elliptic, tapering to the stalks, entire or toothed, 2-15 cm long, 3-25 mm wide, often deciduous, hairy like the stems; stem leaves similar, becoming reduced upwards.
Flowers:
Heads with ray and disk flowers, several to numerous in an open inflorescence, the disk 5-12 mm wide; involucres 2-5 mm tall; involucral bracts finely and obscurely glandular and more or less hairy, subequal, abruptly sharp-pointed or with long-pointed tips, with brown midveins and light greenish or yellowish margins; ray flowers 50-100, white, sometimes pink or bluish, 2-6 mm long, 0.4-1.0 mm wide; disk flowers 1.5-2.6 mm long.
Fruits:
Achenes 2-nerved, hairy; pappus double, the inner of 10-15 fragile bristles, these lacking from the ray flowers, the outer of short bristles or scales.