Water ragwort

Jacobaea erratica (syn. Senecio erraticus), the water ragwort or branched marsh ragwort, is a herbaceous biennial to short-lived perennial in the Asteraceae growing 40–120 cm tall from a short rootstock. Stems are erect, often reddish-tinged below, smooth, and freely branched in the upper half. Lower leaves are oblanceolate and pinnately lobed with a large, broad terminal lobe and several pairs of smaller lateral lobes, withering by flowering time; stem leaves are smaller, deeply pinnatifid with narrow, often again-toothed lobes, the lowest pair of lobes typically spreading outward and the leaf base clasping the stem. The inflorescence is a broad, flat-topped, somewhat irregular corymb of numerous flower heads, each 15–25 mm across; ray florets are bright yellow, 6–13 in number and spreading, surrounding a dense disc of yellow tubular florets. Phyllaries are linear with conspicuous black-tipped apices. Fruits are short, cylindrical, ribbed achenes crowned with a white pappus of capillary bristles. It grows in damp meadows, ditches, and stream banks across much of Europe and western Asia.