Pentanema salicinum

Pentanema salicinum (long known as Inula salicina), the willow-leaved fleabane or Irish fleabane, is an upright herbaceous perennial in the family Asteraceae growing 20–80 cm tall from a creeping rhizome. The slender, somewhat wiry stems are sparsely hairy and bear alternate, narrow, elongate, stalkless, willow-like leaves whose margins and the stems themselves are roughened to the touch. From mid- to late summer the plant produces solitary, long-stalked, daisy-like flower heads 2.5–4 cm across, with 35–70 bright yellow ligulate ray florets surrounding a disc of 100–250 yellow tubular disc florets. The fruit is a small ribbed cypsela bearing a pappus of fine hairs. Native across much of mainland western Europe from Spain to Scandinavia, it grows on damp calcareous grasslands, fen edges, lake margins and open woodland. In the British Isles it is restricted to a single locality in south-central Ireland near Lough Derg and is the subject of a coordinated reintroduction programme.