Hieracium pratense Tausch; Pilosella caespitosa (Dumortier) P. D. Sell & C. West

Plants 20–75 cm. Stems proximally piloso-hirsute (hairs 1–3+ mm) and stipitate-glandular, sometimes stellate-pubescent as well, distally piloso-hirsute (hairs 1–4+ mm), stellate-pubescent, and stipitate-glandular. Leaves: basal 3–8+, cauline 0–2(–5+); blades oblanceolate to lanceolate, 35–120(–180+) × 12–20+ mm, lengths 2–6(–10+) times widths, bases cuneate, margins entire or denticulate, apices rounded to acute, faces usually piloso-hirsute (hairs 1–3+ mm) and stellate-pubescent, sometimes glabrate. Heads 5–25+ in ± umbelliform or congested, corymbiform arrays. Peduncles piloso-hirsute (hairs 1–2.5 mm), stellate-pubescent, and stipitate-glandular. Calyculi: bractlets 5–8+. Involucres campanulate, 7.5–9 mm. Phyllaries 12–18+, apices acute to acuminate, abaxial faces piloso-hirsute (hairs 1–2.5+), stellate-pubescent, and stipitate-glandular. Florets 25–50+; corollas yellow, 8–12+ mm. Cypselae columnar, 1.5–1.8 mm; pappi of 25–30+, white bristles in 1 series, 4–5(–6) mm.

Flowering May–Jul(–Aug). Disturbed sites, stream sides; introduced; 10–300(–1500) m; B.C., Man., N.B., Nfld. and Labr. (Nfld.), N.S., Ont., P.E.I., Que.; Conn., Del., D.C., Ga., Idaho, Ill., Ind., Ky., Maine, Md., Mass., Mich., Minn., Mont., N.H., N.J., N.Y., N.C., Ohio, Pa., R.I., S.C., Tenn., Vt., Va., Wash., W.Va., Wis., Wyo.; Europe.

The type of Hieracium floribundum Wimmer & Grabowski probably resulted from a cross between plants of H. caespitosum and H. lactucella (P. D. Sell and C. West 1976).