Foothill Arnica

Plants 10–75 cm. Stems solitary, simple. Leaves 3–5 pairs, crowded toward stem bases (some or all axils with dense tufts of brown wool); petiolate (petioles at least basal leaves, narrow or broadly winged); blades (with 3 or 5 prom-inent, subparallel veins) usually narrowly oblanceolate to oblong, rarely oval or broadly spatulate, 4.5–20 × 0.5–2.5 cm, margins denticulate, apices obtuse, faces moderately uniformly hairy, stipitate-glandular. Heads 1(–3). Involucres broadly hemispheric. Phyllaries 13–21, elliptic-oblong or narrowly to broadly lanceolate. Ray florets 8–16; corollas yellow-orange. Disc florets: corollas yellow; anthers yellow. Cypselae brown, 3.5–7 mm, densely hirsute, sometimes sparingly stipitate-glandular; pappi usually white, sometimes tawny, bristles barbellate. 2n = 38, 57.

Arnica monocephala Rydberg; A. pedunculata Rydberg

Arnica fulgens Pursh, Fl. Am. Sept. 527. 1814
A mica monlana fulgens Nutt. Gen. 2: 164. 1818. Arnica augustifolia Nutt. Trans. Am. Phil. Soc. II. 7: 407. 1841. Arnica pedunculala Rydb. Bull. Torrey Club 24: 297. 1897. Arnica monocephala Rydb. Mem. N. Y. Bot. Gard. 1: 435. 1900. Arnica pedunculala tubularis Cockerell, Jour. Hered. 7: 228. 1916.
Rootstock usually short and thick, and with dense tufts of brown villous hairs on the crown; stem 2-5 dm. high, striate or sulcate, viscidly short-villous and glandular-puberulent throughout ; offsets rarely present at flowering time, their leaves similar to the basal and lower cauline leaves; basal leaves several, oblanceolate or spatulate, obtuse or rounded at the apex, tapering at the base, with a short winged petiole, 5—1,5 cm. long, strongly 3-5-ribbed, shortvillous and glandular-puberulent on both sides; stem-leaves 2 or 3 pairs, the lowest pair oblanceolate, 6-10 cm. long, tapering below into a winged petiole, the rest linear and the uppermost reduced; heads 1—3, usually solitary; peduncles 5-20 cm. long; involucre hemispheric, 12-14 mm. high, often 2 cm. broad, densely hirsute-villous and somewhat glandular; bracts 15-20, narrowly lanceolate or linear, acute; ray .flowers 10-15, the ligules orange, 14-18 mm. long, 3-6 mm. broad, coarsely 3-toothed at the apex; disk-corollas 8 mm. long; achenes about 8 mm. long, hirsute; pappus-bristles white, barbellate, 8-9 mm. long.
Type locality: Banks of the Missouri.
Distribution: Manitoba to Nebraska, Colorado, Oregon, and British Columbia.

Arnica fulgens is a species of arnica known by the common names foothill arnica and hillside arnica. It is native to western North America, from British Columbia east to Saskatchewan and south as far as Inyo County, California, and McKinley County, New Mexico. It grows in open, grassy areas.

Arnica fulgens is a perennial herb growing from a short, tough rhizome and producing one or more hairy, glandular, mostly naked stems to heights between 10 and 60 centimeters. The leaves are mainly located around the base of the plant. They are broadly lance-shaped to oval-shaped and have tufts of woolly fibers in their axils. They are up to 12 centimeters long, and there may be a few much shorter ones further up the stem.

The inflorescence holds usually one, but sometimes 2 or 3, daisylike flower heads lined in hairy phyllaries. Each head has a center of glandular golden disc florets lined with golden ray florets which are 1 to 3 centimeters long. The fruit is an achene with a hairy body half a centimeter long and a light-colored pappus. Flowers bloom May to July. Arnica fulgens avoid heat and drought by dying back to the rootstalk and re-sprouting the next spring.