Potentilla vahliana

Lehmann

Monogr. Potentill., 172. 1820.

Common names: Vahl's cinquefoil potentille de Vahl
Endemic
Basionyms: Potentilla hirsuta Vahl ex Hornemann in G. C. Oeder et al., Fl. Dan. 8(22): plate 1390. 1810,
Treatment appears in FNA Volume 9. Treatment on page 205. Mentioned on page 196, 198, 203.

Plants densely tufted to cushion-forming. Caudex branches usually stout, columnar, sheathed with marcescent whole leaves. Stems erect, (0.2–) 0.3–0.8 (–1) dm, lengths 2–4 (–5) times basal leaves. Basal leaves 1–3 cm; petiole 0.5–2 cm, long hairs common to abundant, ascending to spreading, 0.5–1.5 (–2) mm, soft to weak, smooth, short hairs absent, crisped/short-cottony hairs sparse to abundant, glands sparse to common; leaflets separate to slightly overlapping, central obovate, 0.8–1.2 (–1.5) × 0.5–1 (–1.5) cm, sessile or subsessile, base cuneate, margins revolute, distal ± 1/2 incised (1/3–) 1/2–3/4 to midvein, teeth 2–3 per side, ± approximate to distant, surfaces ± dissimilar, abaxial yellowish white or grayish, long hairs 1–2 mm, cottony-crisped hairs ± dense, adaxial green to yellowish gray, long (/short) hairs common to abundant, crisped hairs absent or sparse. Cauline leaves 0–1 (–2). Inflorescences 1–2 (–3) -flowered. Pedicels 0.5–1.5 cm in flower, to 3.5 cm in fruit. Flowers: epicalyx bractlets broadly ovate, 2.5–4 (–5) × 1.5–3 mm, ± as wide as sepals, margins flat or revolute, red-glands absent; hypanthium 2–4 mm diam.; sepals 2.5–5 (–6) mm, apex subacute to acute; petals 8–10 × 7–12 mm, significantly longer than sepals; filaments 1–1.2 mm, anthers 0.4–0.6 mm; carpels 30–40, apical hairs absent, styles narrowly columnar, distinctly papillate-swollen at very base, 1–1.1 mm. Achenes 1.1–1.5 mm. 2n = 42, 49, 56.


Phenology: Flowering summer.
Habitat: Gravelly dry tundra, dry ridges, gravel flats, herb slopes, acidic and calcareous bedrock
Elevation: 0–700 m

Discussion

As circumscribed here, Potentilla vahliana is confined to northeastern arctic Canada (including northernmost Quebec) and western Greenland. Plants previously assigned to P. vahliana from northwestern Greenland, Yukon, most of arctic Canada, and Alaska are now relegated to P. subvahliana.

Plants from western Greenland, whence Potentilla vahliana was described and typified, have petioles with at least some short cottony or crisped hairs in addition to long, smooth hairs, and the styles have distinct papillae at the very base. These features are derived from a combination of the P. uniflora Ledebour and P. nivea groups. Potentilla vahliana is of a higher polyploidy than the species of the P. uniflora group. Potentilla vahliana is treated here as a geographically restricted species, most probably from cross(es) between P. nivea in the narrow sense (probably the Atlantic race, often 2n = 70) and P. subvahliana (2n = 28); it shares several features with the latter, not least of which is leaf dissection and the columnar structure of the caudex.

In mainland Quebec, plants combine features from Potentilla arenosa and P. vahliana; that is, the straight hairs are slightly verrucose, not smooth as in P. nivea, P. subvahliana, and P. vahliana in the narrow sense. They form populations and probably should be described as a new hybrid species.

Selected References

None.

Lower Taxa

None.

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

... more about "Potentilla vahliana"
56 +, 49 +  and 42 +
reddish +, yellowish white +, gray +  and white +
cottony-crisped +
reddish +, yellowish white +, gray +  and white +
cottony-crisped +
grayish +  and yellowish white +
cottony-crisped +
rugose +  and smooth +
1.1mm +  and 1.5mm +
green +  and yellowish gray +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.06 cm0.6 mm <br />6.0e-4 m <br />) +
Reidar Elven +, David F. Murray +  and Barbara Ertter +
Lehmann +
compound +  and simple +
1 cm10 mm <br />0.01 m <br /> (3 cm30 mm <br />0.03 m <br />) +
cuneate +
Potentilla hirsuta +
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 +
subsessile +  and sessile +
1.2 cm12 mm <br />0.012 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
1 cm10 mm <br />0.01 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
0.8 cm8 mm <br />0.008 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (1 cm10 mm <br />0.01 m <br />) +
Vahl's cinquefoil +  and potentille de Vahl +
Greenland +, Nunavut +  and Que. +
not +  and aggregated +
0–700 m +
0.4 cm4 mm <br />0.004 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.12 cm1.2 mm <br />0.0012 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 +
Gravelly dry tundra, dry ridges, gravel flats, herb slopes, acidic and calcareous bedrock +
stoloniferous +  and short-rhizomatous +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
straight +
ascending +  and spreading +
sparse +, common +  and abundant +
crisped +  and cottony-crisped +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 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 />) +
0.2 cm2 mm <br />0.002 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 />) +
crassinucellate +
bipinnate +, odd-pinnate +, subpalmate +, palmate +  and ternate +
opposite +  and alternate +
marcescent +
well-developed +
persistent +
cauline +  and basal +
reduced +
separate +  and slightly overlapping +
obtriangular +, suborbiculate +, elliptic +  and obovate +
linear +  and oblanceolate +
palmate +  and pinnate +
1/3 +  and 1/2-3/4 +
revolute +, flat +  and incised +
inferior +  and superior +
clustered +, biseriate +  and superposed +
6 cm60 mm <br />0.06 m <br /> (10 cm100 mm <br />0.1 m <br />) +
0 cm0 mm <br />0 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
1 cm10 mm <br />0.01 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
free +  and distinct +
0.8 cm8 mm <br />0.008 m <br /> (1 cm10 mm <br />0.01 m <br />) +
significantly longer +
0.4 cm4 mm <br />0.004 m <br /> (1 cm10 mm <br />0.01 m <br />) +
0.7 cm7 mm <br />0.007 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (2 cm20 mm <br />0.02 m <br />) +
Flowering summer. +
adnate +, free +, connate +  and distinct +
palmate +  and ternate +
12 cm120 mm <br />0.12 m <br /> (20 cm200 mm <br />0.2 m <br />) +
1 cm10 mm <br />0.01 m <br /> (12 cm120 mm <br />0.12 m <br />) +
Monogr. Potentill., +
not arillate +
0.5 cm5 mm <br />0.005 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
persistent +
free +  and distinct +
erect +  and spreading +
lanceolate +  and broadly ovate or deltate +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
free +  and distinct +
not rooting +
reddish +  and green +
2-4(-5) times basal leaves +
1 +  and many +
not flagelliform +
palmate +  and pinnate +
linear;ovate +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
deciduous +
distinct +
proximal +  and subapical +
papillate-swollen +  and columnar +
rough-thickened +
0.1 cm1 mm <br />0.001 m <br /> (0.11 cm1.1 mm <br />0.0011 m <br />) +
not fleshy-thickened +
Potentilla vahliana +
Potentilla sect. Niveae +
species +
2 +  and 3 +
inconspicuous +
enlarged +
biennial +, annual +  and perennial +
plant +  and cushion-forming +