General:
Perennial herb from creeping rhizomes; stems leafy, erect, unbranched except in inflorescence, usually somewhat hairy and glandular at least in the upper portion, 15-80 cm tall.
Leaves:
Basal leaves small, often deciduous by flowering time; stem leaves opposite, mostly unstalked, usually in 5-10 pairs (sometimes 4), lance-shaped to oblanceolate, toothed, 2-12 cm long, nearly glabrous to glandular-hairy.
Flowers:
Heads with ray and disk flowers, 1-5 (sometimes up to 10), on stalks with yellowish hairs and often stalked glands; involucres 7-15 mm tall; involucral bracts lance-shaped, sharp-pointed, hairy; ray flowers pale yellow, 8-14, 1-2 cm long, conspicuously toothed at tip; disk flowers yellow.
Fruits:
Achenes 4-6.2 mm long, sparsely stiff-hairy, sometimes glandular; pappus brownish, somewhat feathery.