Petasites frigidus (L.) R. E. Fr.

Petasites frigidus (L.) Fries, Summa Veg. Scand. 182. 1845
Tussilagofrigida L. Sp. PI. 865. 1753. Tussilago corymbosa R. Br. Chloris Melv. 21. 1823. Nardosmia angulosa Cass. Diet. Sci. Nat. 34^ 188. 1825. Nardosmia frigida Hook. Fl. Bor. Am. I: 307. 1833. Nardosmia corymbosa Hook. Fl. Bor. Am. 1: 307, in part. 1833.
A perennial, with a horizontal rootstock; scape 2-4 dm. high, floccose; scales lanceolate,
5-8 cm. long, the lower often bearing a small blade; petioles of the basal leaves 1-2 cm. long;
blades triangular-sagittate, with an open basal sinus, coarsely dentate with few broadly
triangular teeth, or sometimes also shallowly lobed, 3-10 cm. long, 3-13 cm. broad, slightly
floccose, soon glabrate above, whitetomentose beneath; inflorescence corymbose; involucre of
the essentially hermaphrodite heads about 1 cm. high and nearly as broad; bracts purplish,
12-15, oblong, obtuse; ray-flowers 15-20, ligulate; corolla-tube 6 mm. long, the ligule 4-5 mm.
long, 2 mm. broad, 5-nerved, spreading; hermaphrodite flowers numerous; corollatube 5 mm.
long, the throat 2 mm. long, funnelform, the lobes 1 mm. long, lanceolate; pappus 3-4 mm.
long; style clavate above; lobes triangular; involucre of the pistillate heads slightly smaller,
similar; flowers usually all pistillate; corolla-tube 6-7 mm. long, slender, the ligule of the
marginal flowers 2 mm. long or less, and less than 0.5 mm. wide, that of the central flowers much
smaller, rudimentary or wanting; achenes fully 2 mm. long; pappus in anthesis 10-12 mm.
long, in fruit often IS mm. long. The Alaskan specimens have usually more rounded-cordate
leaf-blades.
Type locality: Alps of Lapland. Distribution: Arctic America, Europe, and Asia.