Hieracium flagellare var. amauracron (Missback & Zahn) Lepage; H. flagellare var. cernuiforme (Naegeli & Peter) Lepage; H. flagellare var. pilosius Lepage; Pilosella flagellaris (Willdenow) P. D. Sell & C. West

Plants 5–12(–20+) cm. Stems proximally piloso-hirsute (hairs 2–4+ mm) and stellate-pubescent, distally piloso-hirsute (hairs 1–4 mm), stellate-pubescent, and stipitate-glandular. Leaves: basal 8–12+, cauline 0(–2+); blades spatulate to oblanceolate, 20–45(–130+) × 8–20(–25+) mm, lengths 2–3+ times widths, bases cuneate, margins entire, apices rounded to acute, abaxial faces piloso-hirsute (hairs 1–4+ mm) and stellate-pubescent, adaxial piloso-hirsute (hairs 1–4+ mm). Heads 2–4+ in ± umbelliform to corymbiform arrays. Peduncles piloso-hirsute, stellate-pubescent, and stipitate-glandular. Calyculi: bractlets 13–15+. Involucres hemispheric, (9–)12–13 mm. Phyllaries 30–40, apices acuminate, abaxial faces stellate-pubescent, sometimes, piloso-hirsute and stipitate-glandular as well. Florets 90–120+; corollas yellow (often each with abaxial red stripe), 6–10+ mm. Cypselae columnar, 1–2.5 mm; pappi of 25–40+, white bristles in 1 series, 4–5+ mm.

Flowering May. Disturbed sites, roadsides, forest edges; introduced; 10–300(–600+) m; B.C., N.B., N.S., P.E.I., Que.; Conn., Ind., Maine, Mass., Mich., N.H., N.Y., Ohio, Pa., Vt., Va.; Europe.

The type of Hieracium flagellare may have resulted from a cross between plants of H. caespitosum and H. pilosella (A. Cronquist 1980).