Inula L.
Mostly perennial herbs, rarely biennials or small shrubs. Lvs alternate, simple, entire or serrate. Capitula solitary or in corymbs or panicles. Involucral bracts in several rows, imbricate, with erect lamina, the outer usually herbaceous, the inner membranous. Receptacle flat or slightly convex; scales 0. Outer florets usually ♀, ligulate; ligules yellow or orange. Inner florets, or rarely all florets, ⚥, tubular. Achenes all similar, angled or ribbed, not or slightly narrowed below apex; pappus hairs in 1 row, narrow at apex.
Key
c. 80-100 spp., Eurasia, Africa, Madagascar. Naturalised spp. 2.
The free base of the pappus hairs is one of the characters used to distinguish Inula from Dittrichia, but in I. helenium the bases of the pappus hairs are clearly fused.
