Dryas hookeriana L.(Juz.) Hulten
white mountain-avens
Rosaceae (Rose family)

Introduction to Vascular Plants

Photograph

© Ken Marr     (Photo ID #88073)


Map

E-Flora BC Static Map

Distribution of Dryas hookeriana
Click here to view the full interactive map and legend

Species Information

General:
Prostrate shrub from a woody stem-base; stems trailing, freely branching and rooting, forming dense mats.
Leaves:
Alternate, evergreen, the leaf blades oblong-egg-shaped to linear-lanceolate, 0.8-4 cm long, broadest near the middle, blunt to rounded at the tip, rounded to squared-off or somewhat heart-shaped at the stalked base; the margins coarsely blunt-toothed, rolled under; strongly wrinkled, green and mostly smooth but often warty-glandular above, densely white woolly-hairy (rarely nearly smooth) below; midvein below with gland-tipped brown hairs and/or brown scales with long much-branched white hairs; dead leaves withering but the remains persisting.
Flowers:
Solitary, erect on leafless, 5- to 20-cm tall stalks, the stalks more or less woolly and also stalked-glandular above; corollas white, 2-3 cm across, the petals 8 to 10, oblong to elliptic, spreading, 8-17 mm long; calyces white-woolly and with some black, glandular hairs, the 8 to 10 lobes oblong-lanceolate, 4-8 mm long; ovaries superior; stamens numerous, the filaments smooth.
Fruits:
Achenes, numerous, about 3 mm long, with long (to 3 or 4 cm), feathery styles.
Notes:
Hybrids between this species and Dryas integrifolia can occur where the two species grow together. To separate this species from D. octopetala look for egg-shaped leaves, broadest near or below middle; densely white-woolly beneath.

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 Dryas hookeriana

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)
2170 2040 2300
Slope Gradient (%)
51 50 52

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

143 76 212
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
3 3 3
Modal Nutrient Regime
Class
D
# of field plots
 species was recorded in:
2
Modal BEC Zone Class
ESSF

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

ESSF(1), IMA(1)

Habitat and Range

Dry to mesic gravelly slopes and ridgecrests, rocky tundra and heath in the alpine zone; ssp. alaskensis is rare in C BC while the ssp. octopetala and ssp. hookeriana are infrequent in S BC but more common northward; circumboreal, N to AK, YT and NT, S to OR and CO and E to NF.

SourceThe Illustrated Flora of British Columbia

Synonyms

Synonyms and Alternate Names:
Dryas octopetala subsp. hookeriana (Juz.) Hultén