Potentilla nana

D. F. K. Schlechtendal

Ges. Naturf. Freunde Berlin Mag. Neuesten Entdeck. Gesammten Naturk. 7: 296. 1816.

Common names: Dwarf cinquefoil
EndemicIllustrated
Synonyms: Potentilla emarginata subsp. nana (D. F. K. Schlechtendal) Hultén
Treatment appears in FNA Volume 9. Treatment on page 192. Mentioned on page 189.

Plants densely tufted; caudex branches short, slender to ± stout, diam. 0.5–1 cm, including old leaf-bases. Stems ascending to erect, 0.1–0.5 (–0.7) dm, lengths 1–2 times basal leaves. Basal leaves not in ranks, ternate, 1–5 cm; stipules: apex acute; petiole 0.5–3.5 cm, long hairs sparse to abundant, ascending to spreading, 0.5–2 mm, ± soft, glands sparse to common; leaflets 3, central obovate, 0.5–2 × 0.5–1 cm, petiolule 0–1 mm, margins revolute, not lobed, distal 1/2–2/3 evenly incised ± 1/2 to midvein, teeth 3–4 (–6) per side, surfaces ± similar, green (paler abaxially), hairs sparse to abundant, 0.8–1.2 mm, glands sparse to common. Inflorescences 1 (–2) -flowered. Pedicels straight, 0.2–1.5 cm in flower, to 5 cm in fruit. Flowers: epicalyx bractlets oblong or ovate, 2.5–5 × 1.5–3.5 mm, margins revolute; hypanthium 3–3.5 mm diam.; sepals 2.5–5 mm, apex ± acute; petals pale-yellow, 4–8 × 4–6 mm; filaments 1.2–2 mm, anthers 0.3–0.4 mm; carpels 40–50, styles ± columnar, not or scarcely papillate-swollen proximally, 0.8–1.2 mm. Achenes 1.4–1.6 mm.


Phenology: Flowering summer.
Habitat: Alpine and coastal Dryas-Salix-Empetrum heaths, gravelly slopes, ridge crests, fellfields, scree and talus
Elevation: 100–1100 m

Discussion

Potentilla nana has most often been considered a race of P. hyparctica or as the priority name for P. hyparctica. As now defined, P. nana occurs in an arc across southern Alaska, from the Aleutian and Pribilof islands to the Alaskan panhandle and adjacent British Columbia. T. Wolf (1908) treated it as a dwarf form of P. fragiformis; J. Soják (1996) interpreted P. nana as a hybrid species originating from cross(es) between P. fragiformis and P. hyparctica. Although the hybrid hypothesis has morphologic support, P. nana has a unique combination of morphologic features and has a distinct range from both P. fragiformis and P. hyparctica. The species are also ecologically segregated: P. nana is a coastal heath and gravel slope species, like P. hyparctica; P. fragiformis is strictly maritime coastal.

Selected References

None.

Lower Taxa

None.

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

... more about "Potentilla nana"
pale +  and dark green rarely grayish brownish or reddish +
1.4mm +  and 1.6mm +
green +  and dark green rarely brownish or reddish +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.04 cm0.4 mm <br />4.0e-4 m <br />) +
Reidar Elven +, Barbara Ertter +, David F. Murray +  and James L. Reveal +
D. F. K. Schlechtendal +
1 cm10 mm <br />0.01 m <br /> (5 cm50 mm <br />0.05 m <br />) +
Aureae +
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 />) +
reduced +
free +  and distinct +
hairy +  and glabrous +
0.5 cm5 mm <br />0.005 m <br /> (1 cm10 mm <br />0.01 m <br />) +
slender +  and more or less stout +
0.5 cm5 mm <br />0.005 m <br /> (2 cm20 mm <br />0.02 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (1 cm10 mm <br />0.01 m <br />) +
Dwarf cinquefoil +
B.C. +  and Alaska. +
not +  and aggregated +
100–1100 m +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
ovate +  and oblong +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
5-merous +, solitary +  and open +
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 />) +
Alpine and coastal Dryas-Salix-Empetrum heaths, gravelly slopes, ridge crests, fellfields, scree and talus +
stoloniferous +  and short-rhizomatous +
straight +
stiff +, weak +  and more or less stiff +
ascending +  and spreading +
sparse +  and abundant +
crisped +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
not differentiated +
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 /> (0.35 cm3.5 mm <br />0.0035 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 +
not +  and overlapping +
obtriangular +  and flabellate +
linear +  and oblanceolate +
palmate +  and pinnate +
1/2 +  and 2/3 +
incised +  and not lobed +
inferior +  and superior +
clustered +, biseriate +  and superposed +
3 cm30 mm <br />0.03 m <br /> (9 cm90 mm <br />0.09 m <br />) +
0 cm0 mm <br />0 m <br /> (5 cm50 mm <br />0.05 m <br />) +
1 cm10 mm <br />0.01 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
free +  and distinct +
0.4 cm4 mm <br />0.004 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
usually longer +
0.3 cm3 mm <br />0.003 m <br /> (1 cm10 mm <br />0.01 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
0 cm0 mm <br />0 m <br /> (0.1 cm1 mm <br />0.001 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 />) +
usually not much longer +
Ges. Naturf. Freunde Berlin Mag. Neuesten Entdeck. Gesammten Naturk. +
not arillate +
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 />) +
Endemic +  and Illustrated +
free +  and distinct +
not rooting +
reddish +  and green +
1-2 times basal leaves +
ascending +  and erect +
1 +  and many +
not flagelliform +
palmate +  and pinnate +
deciduous +
distinct +
subapical +
papillate-swollen +  and columnar +
rough-thickened +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
Potentilla emarginata subsp. nana +
not fleshy-thickened +
Potentilla nana +
Potentilla sect. Aureae +
species +
3 +  and 4 +
inconspicuous +
enlarged +
matted +  and cushion-forming +
biennial +, annual +  and perennial +