Arrowleaf or arrowhead sweet coltsfoot, pétasite sagitté

Tussilago sagittata Pursh, Fl. Amer. Sept., 531. 1813; Nardosmia sagittata (Pursh) Hooker; Petasites dentatus Blankinship; P. sagittatus (Pursh) A. Gray

Basal leaves: blades palmately or palmati-pinnately nerved, sagittate or triangular to oblong, 2–34 × 2–30 cm (bases sagittate or cordate, sometimes hastate), margins not lobed (subentire, callous-denticulate, or sinuate-dentate, teeth 11–45 per side), abaxial faces densely woolly to villous, adaxial faces usually tomentose, sometimes glabrescent or glabrous. Staminate heads 8–35; ray florets 4–19, corolla laminae 1.1–7.7 mm; disc floret style branches 0.5–2.3 mm, hairy. Pistillate heads 6–34; ray florets 31–139, corolla laminae 0.6–5.4 mm; disc florets: corolla lobes 0.4–1.8 mm, style branches 0.3–1.3 mm, hairy. Pappi (pistillate) to 17.3 mm. 2n = 58, 59, 60.

Flowering early spring. Wet places, shallow standing water or marshy areas, bogs, fens, moist disturbed areas, roadsides, alluvial flats, recent clearcuts, moist woods and forest edges; 10–3000 m; Alta., B.C., Man., N.B., Nfld. and Labr. (Labr.), N.W.T., Nunavut, Ont., Que., Sask., Yukon; Alaska, Colo. Idaho, Mich., Minn., Mont., N.Dak., S.Dak., Wash. Wis., Wyo.