General: Perennial herb from a long, branching rhizome; stems solitary or occasionally a few clustered together, sparsely hairy with multicellular hairs and often glandular, 10-60 cm tall.
Leaves: Basal leaves heart-shaped, often produced on separate short shoots; stem leaves opposite, 2-3 (sometimes 1 or 4) pairs, larger than the basal ones, heart-shaped, becoming lance-shaped above, glandular to hairy, stalked below, unstalked above, coarsely toothed to entire.
Flowers: Heads with ray and disk flowers, 1-3, rarely as many as 7, erect, the bases sparsely to densely hairy with long white hairs, often glandular; ray flowers yellow, usually 9-16, with conspicuous teeth; disk flowers yellow, sparsely hairy; involucres 13-22 mm tall, the bracts lanceolate to oblanceolate, gradually to abruptly pointed, sparsely to densely hairy, often glandular, the tips often fringed.
Fruits: Achenes 4-8 mm long, moderately to densely stiff-hairy, often with stalked glands; pappus white, finely-barbed.
Notes: Arnica cordifolia appears to hybridize with A. latifolia throughout most of its range. These plants are intermediate, especially in leaf characters. In the alpine zone of S BC a smaller phase with narrow, more or less heart-shaped leaves and more glandular achenes has been recognized by some taxonomists as var. pumila (Rydb) Maguire.
Mesic to dry meadows and forests in the montane to alpine zones; common throughout BC east of the Coast-Cascades Mountains, rare on the coast and on SE Vancouver Island; N to AK, YT and NT, E to SK and S to SD, NM, AZ and CA.
The table below shows the species-specific information calculated from original data (BEC database) provided by the BC Ministry of Forests and Range. (Updated August, 2013)
A shade-tolerant/intolerant, montane to subalpine, Western North American forb distributed mainly in the Cordilleran region, marginally in the Pacific and Central regions. Occurs in continental boreal and cool temperate climates on moderately dry to fresh, nitrogen-medium soils; its occurrence increases with increasing elevation and continentality. Grows in meadow-like communities and in open-canopy coniferous forests on high-elevation water-shedding sites in the coast-interior ecotone. Often inhabits exposed mineral soils. Characteristic of continental forests.
BC Ministry of Environment:BC Species and Ecosystems Explorer,
the authoritative source for conservation information in British Columbia.
Synonyms and Alternate Names
Arnica cordifolia subsp. genuina Maguire Arnica cordifolia var. humilis (Rydb.) Maguire Arnica cordifolia var. pumila (Rydb.) Maguire Arnica cordifolia var. whitneyi (Fernald) Maguire Arnica hardinae H. St. John Arnica humilis Rydb. Arnica paniculata A. Nelson Arnica whitneyi Fernald
