Heartleaf Arnica

Arnica pumila Rydb. Mem. N. Y. Bot. Gard. 1: 433. 1900
Arnica panifolia Greene, PI. Baker. 3: 28. 1901. Arnica Evcrmanii Greene, Ottawa Nat. 23: 215. 1910.
Rootstock short, branched; stem 1-2, rarely 3 dm. high, striate, short-villous; leaves of the offsets and basal leaves long-petioled, the petioles 2-5 cm. long, sparingly villous; blades ovate or lanceolate, from cuneate to subcordate at the base, 3-5 cm. long, entire or dentate with few teeth, thick, rather densely short-hairy on both sides; basal leaves usually several; stemleaves 2 or 3 pairs, the lowest pair similar to the basal leaves, upper lanceolate, reduced, sessile; heads 1-3; involucre turbinate, 10-12 mm. high, 15-18 mm. broad, villous and glandularpuberulent; bracts 10-12; ray-flowers 6-10, the ligules 10-15 mm. long, 2-3 mm. wide; diskcorollas 7-8 mm. long; achenes 6 mm. long, hirsute; pappus-bristles 8 mm. long, white, barbellate.
Type locality: (Gray's Peak,) Colorado.
Distribution: Washington to Wyoming, Colorado, and Utah.

Arnica cordifolia Hook. Fl. Bor. Am. 1: 331. 1834
Arnica macrophylla Nutt. Trans. Am. Phil. Soc. II. 7: 408. 1841.
A mica microphylla Walp. Rep. 2: 652. 1843.
Arnica abortiva Greene, Leaflets 2: 47. 1910.
Arnica Andersonii Piper, Proc. Biol. Soc. Wash. 33: 106. 1920.
Rootstock slender, horizontal; stem 2-5 dm. high, sparingly villous; leaves of the offsets long-petioled, the petioles 5-10 cm. long; blades cordate, with a rather open sinus, 4-8 cm. long, coarsely dentate, sparingly villous, acute; stem-leaves 2-4 pairs, the lower two pairs usually long-petioled, similar to those of the offsets, but blades usually more acute and often larger, up to 15 cm. long, the upper 0-2 pairs sessile or subsessile, lanceolate and reduced; leaves of the inflorescence (if heads are more than one) similar but smaller; involucre turbinate, 10-15 mm. high, 15-20 mm. broad, villous; bracts 12-14, oblanceolate, acuminate; rayflowers 8-12, the ligules 1.5-2.5 cm. long, 4-8 mm. wide; disk-corollas 9-1 1 mm. long; achenes 6-8 mm. long, hirsute, striate; pappus-bristles 8-11 mm. long, white, barbellate.
Type locality: Alpine woods in the [Canadian] Rocky Mountains.
Distribution: Alaska and Yukon to Black Hills (South Dakota), New Mexico, and California.