Arctic Sweet Coltsfoot

Petasites hookerianus (Nutt.) Rydberg
Nardosmia Hookeriana Nutt. Trans. Am. Phil. Soc. II. 7: 288. 1841. Petasites palmata frigida Macoun, Cat. Canad. PI. 1: 553. 1886.
A perennial, with a horizontal rootstock; scape 2-4 dm. high, floccose; scales lanceolate, 4-7 cm. long; petioles of the basal leaves 1-4 cm. long; blades reniform or cordate-reniform, 6-15 cm. long, 9-25 arn. wide, glabrate above, white-tomentose beneath, with a wide basal sinus, 7-9-lobed less than halfway to the base; lobes triangular or ovate, dentate; inflorescence corymbiform; involucre of the hermaphrodite plant about 9 mm. high; bracts linear, acute; ray-flowers 15-20; corollatube about 6 mm. long, the ligule oblanceolate, 6-7 mm. long, 1.5 mm. wide; disk-flowers numerous; corolla-tube 5 mm. long, the throat cylindro-campanulate, 2 mm. long, the lobes lanceolate, fully 2 mm. long; anthers 2.5 mm. long; style clavate at the apex, the lobes lanceolate; pistillate plant not known.
Type locality: Not given, but from inference either Bear Lake or the Canadian Rockies. Distribution: Manitoba to Alberta and northward.

Petasites palmatus (Ait.) A. Gray, Bot. Calif. 1 : 407. 1876
Tussilago palmata Ait. Hort. Kew. 3: 188. 1789.
Nardosmia palmata Hook. Fl. Bor.-Am. 1: 308. 1833.
Tussilago lobata Steud. Nom. Bot. ed. 2. 2: 726. 1841.
Nardosmia frigida palmata Herder, Bull. Soc. Nat. Mosc. 38': 372. 1865.
A perennial herb, with a horizontal rootstock; scape 2-4 dm. high; scales 2-6 cm. long, lanceolate, sometimes lobed at the apex; petioles of the basal leaves 1-3 dm. long; blades, reniform in outline, 5-15 cm. long, 7-30 cm. broad, palmately divided to near the base into 7-9 obovate dentate divisions, soon green above, white-tomentose beneath, but in age often only slightly so; basal sinus rather narrow, usually less than 60°; inflorescence at first corymbiform, in age more elongate, with rather long individual peduncles; involucre of the hermaphrodite plant about 9 mm. high and nearly as broad; bracts 10-15, oblong or some of them linear, mostly obtuse; ray-flowers 15-20; tube of the corolla 5 mm. long, the ligule linear, 5 mm. long, 1-1.5 mm. wide; disk-flowers numerous; tube 5 mm. long, the throat campanulate, 1.5 mm. long, the lobes lance-linear; anthers 2 mm. long; style-branches lance-linear, 1 mm. long; involucre of the pistillate plant slightly smaller; pistillate flowers very numerous, fertile; corolla-tube 5 mm. long, the ligules linear, in the marginal flowers 2 mm. long, 0.2 mm. wide, in the inner flowers smaller or wanting; hermaphrodite flowers very few in the center or wanting, their corollas like those of the essentially hermaphrodite plant, but tube shorter and throat comparatively longer; achenes 2 mm. long; pappus in fruit 8-10 mm. long.
Type locality: Newfoundland.
Distribution: Newfoundland and Labrador to Massachusetts, Minnesota, and Alberta.

Petasites speciosus (Nutt.) Piper, Mazama 2: 97. 1901
Nardosmia palmata Hook. Fl. Bor. Am. 1: 308. in part. 1833. Nardosmia speciosa Nutt. Trans. Am. Phil. Soc. II. 7: 288. 1841.
A perennial herb, with a horizontal rootstock; scape 3-5 dm. high, floceose; scales lanceolate, 3-5 cm. long; petioles of the basal leaves 1.5-5 dm. long; blades reniform in outline, 720 cm. long, 10-40 cm. broad, green and more or less hirsute with flat hairs above, especially along the veins, white-tomentose beneath, or in age more glabrate, divided below the middle into 7-9 ovate or cuneate, mucronate-dentate divisions; inflorescence corymbose; individual peduncles in fruit often 5 cm. long; involucre of the essentially hermaphrodite plant turbinate, 10-11 mm. high, 10-12 mm. broad; bracts linear, obtusish; ray-flowers 15-20; corolla-tube 6 mm. long, the ligule oblanceolate, 6 mm. long, 1-1.5 mm. wide; style-branches very short; disk-flowers very numerous; corolla-tube 6 mm. long, the throat 1.5 mm. long, the lobes linear, obtuse, 2 mm. long; anthers 2.5 mm. long; upper part of the style thickened but cylindric, the lobes lanceolate; involucre of the essentially pistillate plant 9-10 mm. high and about 10 mm. broad; bracts narrower; pistillate flowers numerous; corollatube 5 mm. long, the ligules erect, 2-2.5 mm. long, fully 0.5 mm. wide; disk-flowers very few, shorter than in the essentially hermaphrodite heads; achenes 3-3.5 mm. long; pappus 5 mm. long, in fruit up to 15 mm. long.
Type locality: Shady forests of the Oregon [Columbia River] and Willamette. Distribution: British Columbia to California.