Cassiope tetragona (L.) D. Don
four-angled mountain-heather (white arctic mountain heather)
Ericaceae (Crowberry family)

Introduction to Vascular Plants


© Allan Carson     (Photo ID #17741)


E-Flora BC Static Map

Distribution of Cassiope tetragona
Click here to view the full interactive map and legend

Species Information

Coarse dwarf shrub, mat-forming; stems 4-angled, stiff, ascending to erect, 5-30 cm long, finely hairy.
Evergreen, opposite, distinctly in 4 rows, appressed, nearly concealing the stems, egg- to lance-shaped, 2-6 mm long, deeply grooved on the back, conspicuously finely hairy and minutely fringed on outer surface, usually glabrous or glandular on concave inner surface; unstalked.
Solitary in leaf axils to few near branch tips, nodding on stalks 10-25 mm long, longer than the subtending leaves; corollas white or pinkish, bell-shaped, (4) 5-10 mm long, lobes egg-shaped, almost 1/2 the length of the tube; calyces reddish, egg-shaped, 2-2.5 mm long, entire; stamens not enlarged at the base.
Capsules, globe-shaped, glabrous, about 3 mm wide.
Two varieties are recognized in BC:

1. Flowers usually less than 5 (6) mm long, the flower stalks generally less than twice the length of the subtending leaves........................ var. saximontana (Small) C. L. Hitchc.

1. Flowers 6-10 mm long, the flower stalks proportionately longer, more than twice the length of the subtending leaves........................... var. tetragona

SourceThe Illustrated Flora of British Columbia

USDA Species Characteristics

Flower Colour:
Blooming Period:
Late Spring
Fruit/Seed characteristics:
Colour: Brown
Present over the Summer
Source:  The USDA


Ecological Framework for Cassiope tetragona

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




Elevation (metres)
1803 34 3000
Slope Gradient (%)
23 0 84

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

11 0 360
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
3 0 7
Modal Nutrient Regime
# of field plots
 species was recorded in:
Modal BEC Zone Class

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

AT(15), BAFA(127), CWH(1), ESSF(90), IMA(42), MH(5), SWB(30)

Habitat and Range

Moist to dry meadows, heath, and rocky slopes in the subalpine and alpine zones; frequent in BC in and E of the Coast-Cascade Mountains; circumpolar, N to AK, YT, and NT, E to N PQ, and S to WA and MT; Eurasia.

SourceThe Illustrated Flora of British Columbia