Hypochaeris radicata Linnaeus Sp. Pl.. 2: 811. 1753.
Hairy cat’s ear
Perennials, 10–60 cm; taproots vertical, thick, fibrous, caudices woody. Stems (1–15) erect, usually branched (2–3 times at midstem and distally, sparsely bracteate or naked), glabrous or coarsely hirsute proximally. Leaves all basal; blades oblanceolate, lyrate to slightly runcinate, 50-–350 × 5–30 mm, margins coarsely dentate to pinnatifid, faces ± hirsute (hairs coarse, spreading). Heads usually 2–7 in loose arrays, sometimes borne singly. Involucres cylindric or campanulate, 10–25 × 10–20 mm. Phyllaries 20–30, narrowly lanceolate, 3–20 mm, unequal, margins scarious, green to darkened, faces glabrous or sparsely hirsute medially. Florets 10–15 mm, surpassing phyllaries at flowering; corollas bright yellow or grayish green. Cypselae monomorphic, all beaked, beaks 3–5 mm; bodies golden brown, fusiform, 6–10 mm, ribs 10–12, muricate; pappi of whitish bristles in 2 series, outer barbellate, shorter than plumose inner, longest 10–12 mm. 2n = 8.
Flowering Apr–Nov. oak-pine forest , coastal prairie , dunes , waste ground , dry fields , roadside ditches , railroads , lawns ;0–1600 m;Ala.; Alaska; Ark.; Calif.; Colo.; Conn.; Del.; Fla.; Ga.; Idaho; Ill.; Ind.; Ky.; La.; Maine; Md.; Mass.; Mich.; Miss.; Mo.; Mont.; Nev.; N.H.; N.J.; N.Y.; N.C.; Ohio; Oreg.; Pa.; R.I.; S.C.; Tenn.; Tex.; Utah; Vt.; Va.; Wash.; W.Va.; Wis.;Europe; Asia.;
Hypochaeris radicata is recognized by the coarse, perennial habit, stout roots, coarsely hirsute leaves and phyllaries, yellow corollas, and monomorphic, beaked cypselae. It is weedy and invasive in some areas.