Herbs, erect or spreading, annual, 1-5 dm, villous, greenish, yellowish green, or reddish. Stems: caudex absent; aerial flowering stems erect or nearly so, solid, not fistulose, 0.1-0.8 dm, villous. Leaves basal and cauline; basal: petiole 0.1-0.5(-1) cm, blade linear-lanceolate to linear-oblanceolate, 1-4 × 0.1-0.4 cm, white-lanate abaxially, villous and greenish to yellowish green adaxially, margins plane or revolute; cauline sessile, blade linear, 0.5-2.5 × 0.05-0.3 cm, tomentose abaxially, thinly villous or glabrous and greenish adaxially. Inflorescences cymose, open, 5-45 × 3-40 cm; branches villous; bracts 3-8, semileaflike, 5-15 × 0.3-1.5(-2) mm. Peduncles erect or nearly so, straight, slender, (1-)2-5(-7) cm, sparsely villous or glabrous. Involucres campanulate, 1-2 × 2-3 mm, villous; teeth 5, mostly erect to spreading, 1-3 mm. Flowers 1-3 mm; perianth white to rose or yellow, sometimes becoming reddish, glabrous; tepals dimorphic, those of outer whorl oblong-ovate, 2-saccate-dilated proximally, those of inner whorl linear-oblong; stamens mostly included, 1-1.5 mm; filaments mostly pilose proximally. Achenes brown to blackish, lenticular, 1.8-2 mm, glabrous.

Varieties 2 (2 in the flora): w North America, including n Mexico.