Stems 5-12 dm from a stout caudex, puberulent above, glabrous below; lvs chiefly cauline, glabrous or scabrous above, hirsute on the midrib and main veins beneath, ±triple-nerved, sharply serrate, commonly lance-elliptic, acuminate, sessile or nearly so, 6-18 נ1.5-3.5 cm; infl a series of short or elongate, thyrsoid, not at all secund branches, the lower subtended by scarcely or slightly reduced lvs; invol 4-6 mm, its bracts slender, imbricate, acute or acutish, yellowish, the green tip often obscure; rays 10-14, well developed. Cliffs and moist woods; n. Vt. and N.H. to the Gasp顰enins. of Que. and to Nf.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.