Sieversia pentapetala

(Linnaeus) Greene

Pittonia 4: 49. 1899.

Common names: Aleutian or low avens
Illustrated
Basionym: Dryas pentapetala Linnaeus Sp. Pl. 1: 501. 1753
Synonyms: Geum pentapetalum (Linnaeus) Makino
Treatment appears in FNA Volume 9. Treatment on page 58.

Leaves: stipules 2–6 mm; petiole 4–15 mm, proximally expanded and sheathing stems, sheath margins ciliate; leaflets proximally narrowly elliptic, 2–6 mm, margins entire or remotely toothed, distally obovate to rhombic, 8–12 mm, margins sharply lobed or toothed apically. Inflorescences: bracts 3-fid or linear, 6–10 mm; stipule present; petiole reduced to sheathing bases. Pedicels 2.5–8 cm, glabrate to puberulent proximally, puberulent to downy distally. Flowers erect; epicalyx bractlets sometimes 2-fid distally or divided nearly in 2, 3–4 mm; sepals 4–7 mm, margins entire; petals spreading, 7–11 mm, distinctly longer than sepals. 2n = 14.


Phenology: Flowering summer.
Habitat: Moist tundra
Elevation: 0–200[–2700] m

Distribution

V9 82-distribution-map.jpg

Alaska, e Asia (Japan), e Asia (Russian Far East)

Discussion

In North America Sieversia pentapetala is known only from the central Aleutian Islands. Japanese plants are somewhat larger overall than those of the Aleutians.

Selected References

None.

Lower Taxa

None.

"thin" is not a number."elongating" is not a number."dm" is not declared as a valid unit of measurement for this property.

... more about "Sieversia pentapetala"
Joseph R. Rohrer +
(Linnaeus) Greene +
compound +  and simple +
opposite +  and alternate +
Dryas pentapetala +
elliptic +  and obovate +
1 cm10 mm <br />0.01 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
coriaceous +
linear +  and 3-fid +
0.6 cm6 mm <br />0.006 m <br /> (?) +  and 1 cm10 mm <br />0.01 m <br /> (?) +
free +  and distinct +
Aleutian or low avens +
Alaska +, e Asia (Japan) +  and e Asia (Russian Far East) +
not +  and aggregated +
0–200[–2700] m +
divided +  and 2-fid +
0.3 cm3 mm <br />0.003 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
1.5 cm15 mm <br />0.015 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
unisexual +  and bisexual +
not +  and aggregated +
tapered +, ovoid +  and fusiform +
2 cm20 mm <br />0.02 m <br /> (?) +
Moist tundra +
saucer--shaped +
2 cm20 mm <br />0.02 m <br /> (?) +
crassinucellate +
simple +  and compound +
opposite +  and alternate +
deciduous +
narrowly elliptic +  and obovate or rhombic +
0.2 cm2 mm <br />0.002 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
toothed +, lobed +, remotely toothed distally obovate +  and rhombic +
8mm +  and 12mm +
inferior +  and superior +
clustered +, biseriate +  and superposed +
glabrate +  and puberulent proximally +
2.5 cm25 mm <br />0.025 m <br /> (8 cm80 mm <br />0.08 m <br />) +
0 (?) +  and 4 (?) +
fading yellowish +, yellow +  and white +
free +  and distinct +
distinctly longer +
obovate;elliptic +
0.7 cm7 mm <br />0.007 m <br /> (1.1 cm11 mm <br />0.011 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
Flowering summer. +
adnate +, free +, connate +  and distinct +
fibrous-rooted +  and branching +
not arillate +
persistent +
free +  and distinct +
spreading +  and reflexed +
0.4 cm4 mm <br />0.004 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
Illustrated +
free +  and distinct +
decumbent +  and ascending +
1 +  and 5 +
expanded +
palmate +  and pinnate +
0.2 cm2 mm <br />0.002 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
not geniculate-jointed +
persistent +
distinct +
basal +, lateral +, subterminal +  and terminal +
not hooked +
Geum pentapetalum +
Sieversia pentapetala +
Sieversia +
species +
inconspicuous +
short-hairy +
hemispheric +
enlarged +
rhizomatous +  and subscapose +