Bristly Hawksbeard

In Great Britain and/or Ireland:
Foodplant / parasite
Podosphaera fusca parasitises live Crepis setosa

Foodplant / spot causer
hypophyllous colony of Ramularia hyphomycetous anamorph of Ramularia crepidis causes spots on live leaf of Crepis setosa

Crepis setosa is recognized by its annual habit, shallow roots, coarsely setose stems, leaves, and involucres, the relatively large runcinate leaves, sagittate-laciniate cauline leaves, finely beaked cypselae, and white, fine pappus bristles.

Annuals, 8–80 cm (taproots shallow). Stems 1, erect (often reddish), stout (fistulose), simple or branched proximally, coarsely setose or hispid (at least distally, setae yellowish). Leaves basal and cauline; petiolate; blades oblan-ceolate, often runcinate or lyrate, 5–30 × 1–8 cm, margins dentate to pinnately lobed (terminal lobes often relatively large), apices acute to obtuse, faces finely hispid (coarsely setose along midribs; cauline leaves lanceolate, bases sagittate with acuminate lobes, margins dentate to deeply laciniate proximally). Heads 10–20, in paniculiform or cymiform arrays. Calyculi of 10–14, linear, coarsely setose bractlets 2–4 mm. Involucres cylindro-campanulate, 6–10 × 4–10 mm. Phyllaries 12–16, lanceolate, 6–7 mm, (bases strongly keeled and thickened, margins green to yellowish), apices acuminate, abaxial faces coarsely setose or hispid, adaxial with fine hairs. Florets 10–20; corollas yellow, sometimes reddish abaxially, 8–10 mm. Cypselae reddish brown, fusiform, 3–5 mm, beaked (beaks 1–2 mm), ribs 10 (rounded, spiculate near bases of beaks); pappi white (fine, soft), 4 mm. 2n = 8.

Crepis setosa, the bristly hawksbeard, is a European species of flowering plant in the family Asteraceae. It has become naturalized in North America and occurs Washington, Oregon, California, Idaho, Montana, Texas, Arkansas, Missouri, Tennessee, Wisconsin, Ohio, Pennsylvania, New York, Connecticut and Vermont.

Crepis setosa grows in forest and areas with disturbance.