Arctic Sweet Coltsfoot

Petasites alaskanus Rydberg, sp. now
Nardosmia frigida palmata Herder, Bull. Soe. Nat. Mosc. 38 1 : 372. in part. 1865.
A perennial, with a horizontal rootstock; scape 1-2 dm. high, floccose; scales lance-ovate, 3-5 cm. long; petioles of the basal leaves 5-10 cm. long; blades rounded-cordate with the basal lobes incurved and approaching each other, with about 7 shallow coarsely dentate lobes, floccose when young but soon green above, white-tomentose beneath, 5-10 cm. long, 7-15 cm. broad; inflorescence dense, corymbose; involucre of the essentially hermaphrodite plant 8-9 mm. high, 10-12 mm. broad; bracts about 12, oblong, acutish, purple-tinged; ray-flowers 15-20; corollatube 3-4 mm. long, the ligule oblanceolate, 3-4 mm. long, 1.5-2 mm. wide; hermaphrodite flowers numerous; corolla-tube 3-4 mm. long, the throat campanulate, 2 mm. long, the lobes lanceolate, 1-1.5 mm. long; anthers 2 mm. long; tip of the style clavate, the lobes lanceolate; involucre of the pistillate plants similar; flowers usually all pistillate ; corolla of the marginal ones similar to the ray-flowers of the hermaphrodite plant ; those of the rest with smaller erect ligule, linear, 2 mm. long and 0.5 mm. or still smaller; achenes 2 mm. long; pappus in flower 4-5 mm. long, in fruit 1 cm. long.
Type collected on St. Paul's Island, Alaska, 1879, Robert While (herb. Columbia University). Distribution: Alaska.

Petasites gracilis Britton, Bull. X. Y. Bot. Gard. 2: 186. 1901
A perennial, with a slender horizontal rootstock; scape slender, 3-4 dm. high, green,
sparingly floccose; scales few, linear-lanceolate, 3-6 cm. long; petioles of the basal leaves
slender, about 15 cm. long; blades triangular with an open sinus, green above, loosely tomentose
beneath, about 5 cm. long, and 6 cm. wide, with about 12 large triangular cuspidate teeth,
occasionally with a few small secondary ones; inflorescence corymbose-racemose, with slender
peduncles 2-5 cm. long; involucre of the pistillate plant about 7 mm. high; bracts linear,
obtuse, slightly glandular as well as floccose; corolla-tube 4-5 mm. long; ligules erect, linear, 2
mm. long or less, less than 0.5 mm. broad; style-branches short, oblong; achenes 1.5 mm. long;
pappus in fruit 12-15 mm. long; hermaphrodite plant unknown.
Type locality: Walker Gulch, Yukon Territory. Distribution: Yukon and Alaska.

Petasites nivalis Greene, Pittonia 2: 18. 1889
A perennial, with a horizontal rootstock; scape about 3 dm. high, slightly floccose; scales 3-6 cm. long, lanceolate to ovate, sometimes Iobed at the apex; petioles of the basal leaves 1-2 dm. long; blades broadly cordate in outline, or the earlier ones reniform, with an open sinus, 5—15 cm. long and about as broad, glabrate above, white-tomentose beneath, divided halfway or more into 5-7 divisions, which are cuneate in outline, overlapping, usually twice cleft into lanceolate lobes or teeth ; sinuses between the lobes rounded at the bottom, narrow and closed; heads corymbose; involucre of the hermaphrodite plant turbinatc-campanulate, considerably glandular; bracts linear-lanceolate, acute; ray-flowers few, ligulate; corolla-tube 4 mm. long, the ligule spreading, oblanceolate, 4 mm. long, 1.5 mm. wide; disk-flowers many; corolla-tube 4 mm. long, the throat campanulate, 2 mm. long, the lobes lanceolate, 1 mm. long; anthers oblong, 2 mm. long; style clavate at the apex, the lobes lanceolate; pappus 4 nun. long; involucre of the pistillate plant slightly smaller; flowers all pistillate; corolla-tube 4 mm. long, the ligule linear, erect, in the marginal flowers 2 mm. long, 0.2-0.3 mm. wide, in the central flowers minute or wanting; Style branches short, oblong; achenes 1.5 mm, long; pappus iil>oul 5 mm long, in fruit much longer.
Tvpk locality: Alx.ut Cnta Ltletoa Ml Humr. Washington. kiln nOM I SSCSde Mountain* Ol Washington.

Petasites hyperboreus Rydberg, sp. nov
Nardosmia corymbosa Hook. Fl. Bor. Am. 1: 307, mainly. 1833. Not Tussilago corymbosa R. Br.
1823. Nardosmia frigida corymbosa Herder, Bull Soc Nat. Mosc 38 1 : 372. 1865. Petasites corymbosus Rydb. Bull. Torrey Club 37: 460, in part. 1910.
A perennial herb, with a horizontal rootstock; scape 1-3 dm. high, floccose; scales lanceolate, 3-6 cm. long, sometimes with a small blade at the tip; petioles of the basal leaves 5-15 cm. long; blades triangular in outline, with an open sinus, 7-9-lobed, the lobes with 3-4 triangular large teeth, slightly floccose when young but soon glabrous above, white-tomentose beneath, 5-10 em. long, 7-13 cm. broad; inflorescence corymbose; involucre of the hermaphrodite plant nearly 1 cm. high and broad; bracts about 15, linear-lanceolate, acute; rayflowers 10-15; tube of the corolla 6 mm. long, the ligules spatulate, 6 mm. long, 2 mm. wide; disk-corollas numerous; corolla-tube 5 mm. long, the throat funnelform, 2.5 mm. long, the lobes 1.5 mm. long, ovate; style clavate at the apex; lobes oblong, 2 mm. long; pappusbristles about 6 mm. long; involucre of the pistillate plant slightly smaller and the bracts narrower; flowers usually all pistillate and fertile; corolla-tube about 6 mm. long, the ligule erect, linear, of the marginal flowers 2-3 mm. long, about 0.5 mm. wide, that of the central flowers smaller or wanting; achenes 2 mm. long; pappus in anthesis 3-5 mm. long, in fruit 1513 mm. long.
Type collected on second summit west of Skagit River, British Columbia, July, 22, 1905, J. M. Sfacoun 76944 (herb. N. Y. Bot. Gard.).
Distribution: Arctic coast from Hudson Bay to Alaska and south to Alberta and Washington.