Arnica gracilis Rydb.
tall mountain arnica (slender arnica; smallhead arnica)
Asteraceae (Aster family)

Introduction to Vascular Plants

Photograph

© Jim Riley     (Photo ID #28049)


Map

E-Flora BC Static Map

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

Species Information

General:
Perennial herb from a horizontal underground stem; stems erect, solitary or occasionally a few clustered together, sparsely hairy, 10-30 cm tall.
Leaves:
Basal leaves smaller than the stem leaves and often deciduous by flowering time, often produced on separate short shoots; stem leaves opposite, 2-4 (sometimes 5) pairs, egg-shaped to lanceolate, 2-8 cm long, 1-2.5 cm wide, often becoming narrower and smaller above, thinly hairy and usually sparsely to densely glandular, stalked below, unstalked above, usually coarsely toothed.
Flowers:
Heads with ray and disk flowers, 3-9, the bases sparsely to moderately hairy with long white or yellow hairs, often glandular; involucres 7-14 mm tall; involucral bracts lanceolate to oblanceolate, sparsely to densely hairy, often glandular, the tips fringed; ray flowers yellow, 8-12, with conspicuous teeth; disk flowers yellow.
Fruits:
Achenes 4-7 mm long, usually glabrous below and sparsely hairy above or glabrous throughout; pappus white, finely-barbed.

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.

Ecology

Ecological Framework for Arnica gracilis

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)
2255 1754 2555
Slope Gradient (%)
46 7 70

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

175 58 360
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
2 1 5
Modal Nutrient Regime
Class
B
# of field plots
 species was recorded in:
12
Modal BEC Zone Class
ESSF

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

AT(1), ESSF(8), IMA(2), SBS(1)

Habitat and Range

Mesic to dry meadows and rocky slopes in the lowland to alpine zones; common in S BC; E to AB and S to WY and WA.

SourceThe Illustrated Flora of British Columbia

Synonyms

Synonyms and Alternate Names:
Arnica latifolia var. gracilis (Rydb.) Cronquist