Arnica fulgens aka Foothill Arnica

Arnica fulgens is a perennial in the daisy family, Asteraceae. Its common names include hillside arnica and foothill arnica. It comes from western and central parts of North America. Its Canadian range includes British Columbia, Alberta, Saskatchewan, and Manitoba. In the United States, it spans western and west-central states. These include Washington, Oregon, California, the Dakotas, and several inland states. It is not native to Britain or Ireland. The RHS also lists the name Arnica pedunculata as a synonym.

This plant grows to about 2 feet (0.6 metres) tall. In the wild, it grows in open ground in foothills. It also occurs at moderate heights in the mountains. These habitats help explain its use at a sunny woodland edge. Its perennial habit means it grows for more than one year. Each flower has both male and female organs. Insects pollinate the flowers. The supplied species evidence gives no flowering months or mature width.

For garden growth, choose moist soil that drains well. PFAF recommends soil rich in humus and, where possible, free of lime. It also suggests a mix of sand, loam, and peat. The species can grow in sandy, loamy, or clay soils. Good drainage remains important across those soil types. Mildly acid to neutral soil suits it. It can grow in full sun or light woodland shade. PFAF lists it for USDA zones 4–8.

Seed and spring division offer two ways to raise more plants. Sow seed in early spring in a cold frame. Cover it only lightly, and keep the compost from drying out. Move seedlings into separate pots once they are large enough. Keep young plants in a greenhouse or cold frame through their first winter. Plant them out in late spring or early summer. Established plants can also be divided in spring. PFAF does not flag the species as weedy.

This is not a food plant. PFAF lists no known edible uses and warns that all parts are toxic. It records medicinal use, with flowers and roots among the parts used. Reported uses include external treatments for bruises and sprains. These records do not establish safety or prove that treatments work. PFAF limits external use to skin without cuts or breaks. Its toxicity makes it unsuitable for casual home remedies or internal use.