Arnica cordifolia Hook.
heart-leaved arnica (heartleaf arnica)
Asteraceae (Aster family)

Introduction to Vascular Plants

Photograph

© Gordon Neish     (Photo ID #19240)


Map

E-Flora BC Static Map

Distribution of Arnica cordifolia
Click here to view the full interactive map and legend

Species Information

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.

SourceThe Illustrated Flora of British Columbia

Illustration

If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.

USDA Species Characteristics

Flower Colour:
Yellow
Blooming Period:
Late Spring
Fruit/Seed characteristics:
Colour: White
Present from Summer to Fall
Source:  The USDA

Ecology

Ecological Framework for Arnica cordifolia

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)

Site Information
Value / Class

Avg

Min

Max

Elevation (metres)
1271 6 2854
Slope Gradient (%)
22 0 420

Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]

263 0 360
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
3 0 8
Modal Nutrient Regime
Class
C
# of field plots
 species was recorded in:
8118
Modal BEC Zone Class
ESSF

All BEC Zones (# of stations/zone) species was recorded in

AT(27), BAFA(4), BG(3), BWBS(567), CWH(12), ESSF(2270), ICH(484), IDF(966), IMA(3), MH(13), MS(1336), PP(43), SBPS(263), SBS(1349), SWB(113)

Habitat and Range

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.

SourceThe Illustrated Flora of British Columbia

Synonyms

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