Potentilla anserina subsp. yukonensis

(Hultén) Soják ex Elven & D. F. Murray

J. Bot. Res. Inst. Texas 2: 441. 2008.

Common names: Yukon silverweed
EndemicIllustrated
Basionym: Potentilla yukonensis Hultén Fl. Alaska Yukon 6: 1033. 1946,
Synonyms: P. anserina var. yukonensis (Hultén) B. Boivin P. egedei subsp. yukonensis (Hultén) Hultén
Treatment appears in FNA Volume 9. Treatment on page 129. Mentioned on page 127, 128.

Stems sparsely to densely hairy, rarely glabrous. Leaves horizontal to erect, 4–20 cm, rarely longer; leaflets (4–) 5–8 (–9) per side, separate, rarely overlapping, teeth (3–) 5–9 per side, teeth apex acute to acuminate (more sharply than in other subspp.), surfaces: abaxial with long hairs common to abundant, on and between veins, cottony-crisped hairs dense, adaxial sparsely to densely hairy, rarely glabrous. Flowers 1.2–2.2 cm diam.; epicalyx bractlets usually linear to elliptic, longer than sepals, rarely subequal, often 2-fid or dentate; hypanthium turbinate (as deep as wide) in fruit; petals not overlapping, elliptic; carpels 20–60. Achenes with dorsal groove.


Phenology: Flowering summer.
Habitat: Dry sandy and gravelly stream- and lakeshores, dry pastures, open dry pine forests, inland alkaline habitats, road verges and gravelly sites
Elevation: 0–800 m

Distribution

V9 183-distribution-map.jpg

Alta., Man., N.W.T., Sask., Yukon, Alaska.

Discussion

Subspecies yukonensis seems to be the predominant subspecies in interior northwestern Canada and Alaska and is perhaps the only native race in interior Northwest Territories, Yukon, and Alaska. The range is probably larger than reported here. While the flowers of other subspecies generally remain erect, those of subsp. yukonensis tend to nod in fruit.

A. Rousi (1965) suggested that there might be an additional, densely hairy subspecies (undescribed) in western North America. The northern plants observed by the authors mostly share the distinctive hypanthium character with subsp. yukonensis and are assigned here.

Selected References

None.

Lower Taxa

None.

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

0.2 cm2 mm <br />0.002 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
glabrous +  and hairy +
cottony-crisped +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
papillate +  and rugose +
green +  and white +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.13 cm1.3 mm <br />0.0013 m <br />) +
subacute;acuminate +
Reidar Elven +  and David F. Murray +
(Hultén) Soják ex Elven & D. F. Murray +
compound +  and simple +
Potentilla yukonensis +
25 cm250 mm <br />0.25 m <br /> (30 cm300 mm <br />0.3 m <br />) +
less cordate or reniform +  and narrowly elliptic +
0.5 cm5 mm <br />0.005 m <br /> (25 cm250 mm <br />0.25 m <br />) +
coriaceous +
reduced +
free +  and distinct +
hairy +  and glabrous +
Yukon silverweed +
Alta. +, Man. +, N.W.T. +, Sask. +, Yukon +  and Alaska. +
not +  and aggregated +
0–800 m +
0.7 cm7 mm <br />0.007 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
dentate +  and 2-fid +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.45 cm4.5 mm <br />0.0045 m <br />) +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
1.2 cm12 mm <br />0.012 m <br /> (2.2 cm22 mm <br />0.022 m <br />) +
unisexual +  and bisexual +
not +  and aggregated +
deciduous +
on style scar +, hairy +  and glabrous +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.26 cm2.6 mm <br />0.0026 m <br />) +
Dry sandy and gravelly stream- and lakeshores, dry pastures, open dry pine forests, inland alkaline habitats, road verges and gravelly sites +
stoloniferous +  and short-rhizomatous +
straight +
cottony +  and crisped-cottony +
common +  and abundant +
cottony-crisped +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
0.7 cm7 mm <br />0.007 m <br /> (1 cm10 mm <br />0.01 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
0.5mm;2.5mm +
racemiform open +  and more or less congested +
crassinucellate +
5 cm50 mm <br />0.05 m <br /> (7 cm70 mm <br />0.07 m <br />) +
2 cm20 mm <br />0.02 m <br /> (3 cm30 mm <br />0.03 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (5 cm50 mm <br />0.05 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (2 cm20 mm <br />0.02 m <br />) +
bipinnate +, odd-pinnate +, subpalmate +, palmate +  and ternate +
opposite +  and alternate +
marcescent +
well-developed +
persistent +
horizontal;erect +
cauline +  and basal +
reduced +
4 cm40 mm <br />0.04 m <br /> (20 cm200 mm <br />0.2 m <br />) +
overlapping +  and separate +
elliptic +  and obovate +
linear +  and oblanceolate +
palmate +  and pinnate +
1/4 (?) +  and 1/2 (?) +
incised +, flat +  and revolute +
inferior +  and superior +
clustered +, biseriate +  and superposed +
45 cm450 mm <br />0.45 m <br /> (55 cm550 mm <br />0.55 m <br />) +
2 cm20 mm <br />0.02 m <br /> (45 cm450 mm <br />0.45 m <br />) +
not overlapping +
1.5 cm15 mm <br />0.015 m <br /> (2 cm20 mm <br />0.02 m <br />) +
1.5 cm15 mm <br />0.015 m <br /> (2 cm20 mm <br />0.02 m <br />) +
1 cm10 mm <br />0.01 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
bright-yellow +
free +  and distinct +
5mm;15mm +
commonly obcordate;nearly round +
0.5 cm5 mm <br />0.005 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (1 cm10 mm <br />0.01 m <br />) +
15 cm150 mm <br />0.15 m <br /> (25 cm250 mm <br />0.25 m <br />) +
1 cm10 mm <br />0.01 m <br /> (15 cm150 mm <br />0.15 m <br />) +
Flowering summer. +
adnate +, free +, connate +  and distinct +
50 cm500 mm <br />0.5 m <br /> (75 cm750 mm <br />0.75 m <br />) +
3 cm30 mm <br />0.03 m <br /> (50 cm500 mm <br />0.5 m <br />) +
J. Bot. Res. Inst. Texas +
not arillate +
0.7 cm7 mm <br />0.007 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
persistent +
free +  and distinct +
erect +  and spreading +
lanceolate +  and broadly ovate or deltate +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
Endemic +  and Illustrated +
free +  and distinct +
reddish +  and green +
prostrate +  and erect +
lateral;more or less persistent basal +
glabrous;hairy +
1 +  and many +
flagelliform +
palmate +  and pinnate +
linear;ovate +
deciduous +
distinct +
papillate-swollen +  and columnar-filiform +
rough-thickened +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
P. anserina var. yukonensis +  and P. egedei subsp. yukonensis +
not fleshy-thickened +
Potentilla anserina subsp. yukonensis +
Potentilla anserina +
subspecies +
5 (?) +  and 9 (?) +
inconspicuous +
enlarged +
biennial +, annual +  and perennial +
herb +  and matted +