The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links
Dryas hookeriana

Hooker's mountain-avens, mountain avens, white dryas, White Mountain-avens

crenulate-leaf mountain avens

Habit Plants 1.5–9 cm. Plants 1–9.5 cm.
Leaf

blades usually oblong-elliptic to lanceolate, sometimes ovate, 4–16(–25) × 1–6(–10) mm, base usually truncate or cordate, sometimes cuneate, margins strongly revolute to flat, coarsely dentate or serrate, sinuses 5–25(–30)% to midvein, apex acute to obtuse, surfaces smooth to slightly plicate, only midvein ± obscured adaxially within medial fold, abaxial tomentose to woolly (obscuring lateral veins), adaxial usually glabrous, sometimes sparsely hairy proximally on midvein, feathery hairs usually absent, rarely 1+ on midveins abaxially, midveins and petioles abaxially stipitate-glandular.

blades oblong-elliptic to lanceolate, 4–16(–25) × 1–6(–10) mm, base usually cuneate, sometimes truncate or cordate, margins strongly revolute to entire, usually serrate or crenate, sometimes dentate, sinuses 5–30% to midvein, apex acute to slightly obtuse, surfaces smooth to rugulose, only midvein ± obscured adaxially within medial fold, abaxial tomentose (obscuring lateral veins), adaxial usually glabrous, sometimes tomentose, feathery hairs usually absent, rarely 1–3 on midveins abaxially, midveins and petioles abaxially not stipitate-glandular, sessile glands usually present, rarely absent, longer hairs on adaxial surface and petioles sparse.

Peduncles

10–30 mm.

17–150 mm.

Flowers

erect at flowering;

sepals lanceolate to narrowly elliptic, 4–10 × 0.6–1.5 mm;

petals 8, spreading, usually white or cream, sometimes yellow, 9–14 × 5–11 mm;

filaments glabrous.

erect at flowering;

sepals lanceolate to narrowly elliptic, 4–8 × 0.7–2.5 mm;

petals 8, spreading, usually white or cream, sometimes yellow, 9–14 × 5–11 mm;

filaments glabrous.

Achenes

2.5–3 mm;

styles 11–25 mm.

2.2–3.5 mm;

styles 11–25 mm.

2n

= 18.

= 18 (Siberia).

Dryas hookeriana

Dryas incisa

Phenology Flowering Jun–Aug. Flowering Jun–Aug.
Habitat Alpine meadows, dry rocky slopes and ridges, alpine tundra Alpine rocky limestone slopes, heath meadows, dry gravel, mesic tundra meadows, outwash plains
Elevation 1500–3900 m (4900–12800 ft) 0–1800 m (0–5900 ft)
Distribution
from FNA
AK; CO; ID; MT; OR; UT; WA; WY; AB; BC; NT
[WildflowerSearch map]
from FNA
AK; NT; YT; Asia (Russian Far East, Siberia)
[BONAP county map]
Discussion

In some states and provinces, the distribution of Dryas hookeriana is restricted to northwestern and central Colorado, southeastern and northernmost Idaho, western and central Montana, northeastern Utah (Uinta and Wasatch mountains), eastern Oregon and Washington, southwestern and central Wyoming, and western Northwest Territories.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Occasional plants without feathery hairs identified as Dryas ajanensis subsp. beringensis are likely D. incisa.

Dryas crenulata Juzepczuk and D. integrifolia subsp. crenulata (Juzepczuk) Scoggan have been misapplied to D. incisa, for example, by A. E. Porsild and W. J. Cody (1980) and Cody (2000). Dryas crenulata is of eastern Siberia (B. A. Jurtzev 1984).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 9, p. 329. FNA vol. 9, p. 328.
Parent taxa Rosaceae > subfam. Dryadoideae > tribe Dryadeae > Dryas Rosaceae > subfam. Dryadoideae > tribe Dryadeae > Dryas
Sibling taxa
D. ajanensis, D. alaskensis, D. drummondii, D. incisa, D. integrifolia, D. octopetala
D. ajanensis, D. alaskensis, D. drummondii, D. hookeriana, D. integrifolia, D. octopetala
Synonyms D. octopetala var. angustifolia, D. octopetala subsp. hookeriana, D. octopetala var. hookeriana
Name authority Juzepczuk: Izv. Glavn. Bot. Sada S.S.S.R. 28: 325. (1929) Juzepczuk: Izv. Glavn. Bot. Sada S.S.S.R. 28: 312, 323. (1929)
Web links