Potentilla pedersenii

(Rydberg) Rydberg in N. L. Britton et al.

in N. L. Britton et al., N. Amer. Fl. 22: 332. 1908.

Basionyms: Potentilla subquinata var. pedersenii Rydberg Bull. Torrey Bot. Club 28: 182. 1901
Synonyms: P. tolmatchevii Jurtzev & Soják
Treatment appears in FNA Volume 9. Treatment on page 210. Mentioned on page 207, 211, 212.

Caudex branches not sheathed with marcescent whole leaves. Stems ascending to nearly erect, 0.4–2 dm. Basal leaves often both ternate and palmate or subpalmate on same plant, 2.5–4 cm; petiole 1.5–2.5 cm, long hairs common to abundant, loosely appressed to ascending-spreading, 1–2 mm, weak to ± stiff, verrucose, crisped (/short) hairs absent or sparse to common, cottony hairs absent, glands sparse to common; leaflets 3–5, proximalmost separated by 0–2 mm, central broadly elliptic to obovate, 1–1.5 × 0.5–0.9 cm, petiolules 1–2 mm, distal 2/3–3/4 of margin incised 1/2–3/4 to midvein, teeth (2–) 3–4 per side, 4–6 mm, apical tufts ± 1 mm, abaxial surfaces grayish white to white, long hairs abundant (sometimes obscuring entire surface), cottony-crisped hairs abundant to dense, short hairs absent or obscured, glands sparse to common but usually obscured, adaxial grayish green to gray, long hairs sparse to abundant, 1–1.5 (–2) mm, ± weak, short (short-crisped) hairs absent or sparse, rarely common, cottony hairs absent, glands absent or sparse, rarely common. Cauline leaves 0–2. Inflorescences (1–) 3–7-flowered, open, branch angle 30–50°. Pedicels 1–2 cm, proximal to 4 cm. Flowers: epicalyx bractlets narrowly ovate to elliptic, 4–5 × 1–1.4 mm; hypanthium 3–4 mm diam.; sepals 4–6 mm, apex subacute to acute, glands sparse to common, usually not obscured; petals pale-yellow, usually not overlapping, 6–7 × 4–8 mm, distinctly longer than sepals; filaments 1–2 mm, anthers ± 0.4 mm; carpels 40–80, styles 0.8–0.9 mm. Achenes 1.1–1.2 mm.


Phenology: Flowering summer.
Habitat: Dry tundra, gravel and loam ridges, loam flats, rocky outcrops and crevices
Elevation: 0–200 m

Distribution

V9 318-distribution-map.jpg

Greenland, N.W.T., Nunavut, ne Europe, n Asia

Discussion

Potentilla pedersenii and P. uschakovii account for the majority of arctic populations previously included in a broadly defined P. rubricaulis. The diagnostic morphological characters between the two species can be variable and overlapping; they are treated separately in part because of differences in presumed parental combinations. Whereas P. pulchella is the probable sect. Pensylvanicae parent for both species, the putative sect. Niveae parent for P. pedersenii is P. arenosa subsp. arenosa; that of P. uschakovii is P. subvahliana. Reflecting this parentage, P. pedersenii is distinguished by caudex branches with no marcescent whole leaves, verrucose long hairs on petioles, and inflorescences with usually several relatively small flowers. In contrast, P. uschakovii often has marcescent whole leaves sheathing the caudex branches, smooth long hairs on petioles, and one- or few-flowered inflorescences with mostly larger flowers. These generalities aside, there is much variation within both species, such that each island or population group may have its own features; it is probable that both P. pedersenii and P. uschakovii have evolved from multiple hybridization events.

Selected References

None.

Lower Taxa

None.

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

... more about "Potentilla pedersenii"
green +  and gray +
not glaucous +  and cottony +
grayish white +  and white +
not glaucous +  and cottony +
smooth +  and faintly rugose +
1.1mm +  and 1.2mm +
grayish green +  and gray +
0.4 cm4 mm <br />0.004 m <br /> (?) +
Reidar Elven +  and Barbara Ertter +
(Rydberg) Rydberg in N. L. Britton et al. +
subpalmate +, palmate +  and ternate +
opposite +  and alternate +
2.5 cm25 mm <br />0.025 m <br /> (4 cm40 mm <br />0.04 m <br />) +
Potentilla subquinata var. pedersenii +
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 +
broadly elliptic +  and obovate +
0 cm0 mm <br />0 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
Greenland +, N.W.T. +, Nunavut +, ne Europe +  and n Asia +
not +  and aggregated +
0–200 m +
0.4 cm4 mm <br />0.004 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
narrowly ovate +  and elliptic +
0.1 cm1 mm <br />0.001 m <br /> (0.14 cm1.4 mm <br />0.0014 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
0.8 cm8 mm <br />0.008 m <br /> (2 cm20 mm <br />0.02 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 />) +
crisped +
Dry tundra, gravel and loam ridges, loam flats, rocky outcrops and crevices +
stoloniferous +  and short-rhizomatous +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
straight +
weak +  and more or less stiff +
loosely appressed +  and ascending-spreading +
common +, sparse +  and abundant +
verrucose +
cottony-crisped +  and crisped +
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 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 /> (0.4 cm4 mm <br />0.004 m <br />) +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
open +  and (1-)3-7-flowered +
crassinucellate +
bipinnate +, odd-pinnate +, subpalmate +, palmate +  and ternate +
opposite +  and alternate +
marcescent +
well-developed +
persistent +
cauline +  and basal +
reduced +
oblanceolate +  and obovate oblong or elliptic +
linear +  and oblanceolate +
palmate +  and pinnate +
1/2 +  and 3/4 +
inferior +  and superior +
clustered +, biseriate +  and superposed +
2 cm20 mm <br />0.02 m <br /> (5 cm50 mm <br />0.05 m <br />) +
1 cm10 mm <br />0.01 m <br /> (2 cm20 mm <br />0.02 m <br />) +
overlapping +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
free +  and distinct +
0.6 cm6 mm <br />0.006 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
distinctly longer +
0.3 cm3 mm <br />0.003 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
1.5 cm15 mm <br />0.015 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
1/2 +  and 3/4 +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
Flowering summer. +
adnate +, free +, connate +  and distinct +
ternate +, usually palmate +  and subpalmate +
1 cm10 mm <br />0.01 m <br /> (10 cm100 mm <br />0.1 m <br />) +
0 cm0 mm <br />0 m <br /> (4 cm40 mm <br />0.04 m <br />) +
1 cm10 mm <br />0.01 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
in N. L. Britton et al., N. Amer. Fl. +
not arillate +
persistent +
free +  and distinct +
erect +  and spreading +
lanceolate +  and broadly ovate or deltate +
0.4 cm4 mm <br />0.004 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
free +  and distinct +
not rooting +
reddish +  and green +
(1-)1.5-4(-6) times basal leaves +
ascending +  and nearly erect +
1 +  and many +
not flagelliform +
palmate +  and pinnate +
linear;ovate +
deciduous +
distinct +
subapical +
papillate-swollen +, less columnar +  and tapered +
rough-thickened +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.09 cm0.9 mm <br />9.0e-4 m <br />) +
P. tolmatchevii +
not fleshy-thickened +
Potentilla pedersenii +
Potentilla sect. Rubricaules +
species +
3 +  and 4 +
0.4 cm4 mm <br />0.004 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
inconspicuous +
enlarged +
biennial +, annual +  and perennial +
herb +  and matted +