Dryas hookeriana |
Dryas incisa |
|
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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 |
AK; CO; ID; MT; OR; UT; WA; WY; AB; BC; NT
|
AK; NT; YT; Asia (Russian Far East, Siberia) |
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 | ||
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) |
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