Helenium L.
Annual or perennial herbs. Lvs alternate, simple, entire or serrate, often decurrent. Capitula pedunculate, solitary or in loose cymes. Involucral bracts in 2-3 rows, foliaceous or membranous. Receptacle convex, ovoid, or conic; scales 0. Outer florets usually ♀, sometimes sterile, ligulate, usually yellow. Inner florets ⚥, tubular, sometimes all florets tubular and ligules 0. Achenes all similar, not compressed, 4-5-angled, narrowed to base, ribbed, often hairy on ribs and angles; pappus of 5-10, often aristate and laciniate scales.
Key
Ligules conspicuous, mostly 15-20 mm long; at least lower and mid cauline lvs shallowly serrate
40 spp., N. America. Naturalised spp. 2.
