Solidago L.
Usually perennial herbs, rarely shrubs. Lvs alternate, simple, entire or serrate. Capitula several to numerous in racemose or corymbose panicles. Involucral bracts in 3-several rows, imbricate, mostly chartaceous. Receptacle flat or convex; scales usually 0, sometimes few. Outer florets ♀, usually ligulate, very rarely filiform, often as many as or more than disc florets, usually in 1 row; ligules yellow. Inner florets ⚥, tubular. Achenes all similar, obovoid to cylindric, terete or angled, ribbed, glabrous or hairy; pappus of scabrid hairs in 1 row.
Key
2
Infl. lax, the branches mostly spreading and secund; lvs 3-nerved; disc florets 3-5-(6)
Infl. dense, the branches erect with capitula on all sides; lvs indistinctly pinnately veined; disc florets c. 8-9
c. 100 spp., mostly N. America, few in Eurasia and S. America. Naturalised spp. 3.
