Plants 30-75(-200) cm. Stems proximally piloso-hirsute (hairs 6-15+ mm), distally piloso-hirsute (hairs 3-10+ mm), sometimes stellate-pubescent as well. Leaves: basal 3-8+, cauline (3-)6-12+; blades oblanceolate, 45-80(-250+) × 12-30(-40+) mm, lengths 4-7+ times widths, bases cuneate, margins entire, apices rounded to acute, faces piloso-hirsute (hairs 3-8+ mm). Heads 10-20+ in paniculiform to nearly racemiform arrays. Peduncles stellate-pubescent and stipitate-glandular, sometimes piloso-hirsute as well. Calyculi: bractlets 9-13+. Involucres campanulate, 6-8(-10) mm. Phyllaries 12-21+, apices acuminate, abaxial faces stellate-pubescent and stipitate-glandular. Florets 30-40(-60); corollas yellow, ca. 7 mm. Cypselae urceolate, 3-4+ mm; pappi of 35-40+, stramineous to sordid bristles in 2+ series, 5.5-6.5 mm. Flowering Jul-Sep. Fields, prairies, roadsides; 100-400 m; Ont.; Ark., Ill., Ind., Iowa, Kans., Ky., La., Mich., Minn., Mo., Nebr., Ohio, Okla., Tenn., Tex., Wis. Hieracium longipilum may be no longer present in Quebec.