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Norwegian cinquefoil, Pennsylvania cinquefoil, pennsylvanian cinquefoil, potentille de pennsylvanie, prairie cinquefoil

branch cinquefoil

Stems

ascending to erect, (0.3–)1–4(–6) dm.

(0.5–)1.5–4(–5.5) dm, lengths 2–3(–4) times basal leaves.

Basal leaves

pinnate, (2–)4–20(–25) cm;

petiole 1–8 cm, long hairs sparse to abundant, rarely absent, spreading to ascending, 0.5–3 mm, weak to ± stiff, short hairs abundant to dense, rarely absent, cottony or crisped hairs absent, glands sparse to abundant, often obscured;

leaflets (2–)3–5(–7) per side, on distal 1/2–3/5 of leaf axis, separate to scarcely overlapping, terminal ones narrowly to broadly oblanceolate, (1–)1.5–5(–6) × 0.5–1.5(–2) cm, margins strongly revolute, incised ± 3/4 to midvein, sometimes more or only ± 1/2, undivided medial blade 2–4(–8) mm wide, teeth 4–8(–10) per side, triangular-ovate to linear-elliptic, surfaces usually ± dissimilar, abaxial ± grayish to nearly white, rarely green, long hairs sparse to abundant (mostly on veins), rarely absent, 0.5–1.5 mm, ± weak, short hairs usually abundant to dense, rarely absent, crisped and cottony hairs absent, glands ± abundant, sometimes obscured, adaxial green to gray-green, long hairs sparse to abundant, rarely absent, spreading to ascending, ± 1 mm, short hairs ± abundant, sometimes obscured, rarely absent, cottony and crisped hairs absent, glands ± abundant.

pinnate, (3–)5–15(–25) cm;

petiole 0.5–5(–8) cm, long hairs absent to abundant, ± appressed, 1–3 mm, stiff to weak, short and crisped hairs absent or obscured, cottony hairs abundant (at least on first-formed leaves), glands sparse or obscured;

leaflets not conduplicate, lateral ones evenly to unevenly paired, 2–5(–7) per side (secondary leaflets sometimes interspersed) on distal 1/3–1/2 of leaf axis, distal pairs usually not decurrent or confluent with terminal leaflet, larger leaflets oblanceolate to narrowly obovate, 1–2.5(–3) × 0.3–1.3(–1.8) cm, distal (1/2–)2/3–3/4 (rarely more) of margin incised ± 1/2 to midvein, teeth (1–)2–9 per side, 1–4 mm, surfaces similar, gray to white or ± green, abaxial: long hairs sparse to common (at least on veins), 0.5–1.5 mm, weak to stiff, short or crisped hairs absent or sparse, sometimes obscured, cottony hairs absent or sparse to dense, glands absent, sparse, or obscured, adaxial: long hairs absent or sparse to common, short or crisped hairs absent or sparse, cottony hairs absent or sparse to abundant, glands absent or sparse.

Cauline leaves

1–4.

2–6+.

Inflorescences

(1–)3–40-flowered, congested or elongating in fruit.

7–30-flowered.

Pedicels

0.2–1 cm (proximal to 3.5 cm).

0.3–3 cm.

Flowers

epicalyx bractlets usually ± lanceolate-elliptic, rarely ± ovate-elliptic, 3–6(–8) × (1–)1.5–2(–2.5) mm, lengths ± equal to sepals, margins ± revolute;

hypanthium 3–6 mm diam.;

sepals (3–)4–6(–8) mm, apex acute to obtuse, abaxial surfaces: venation indistinct, glands abundant, ± evident;

petals pale to bright yellow, (3–)4–7 × (3–)4–7 mm, lengths ± equal to sepals;

filaments (0.5–)1–2 mm, anthers 0.5–0.8(–1) mm;

carpels 50–100, styles papillate-swollen in proximal ± 1/2, ± 1 mm.

epicalyx bractlets linear to narrowly lanceolate, 1–2.5(–3) × 0.3–1 mm, 1/2–2/3 as long as sepals, abaxial vestiture often much sparser than sepals, often glabrate or glabrescent distally, straight hairs absent or sparse, cottony hairs usually abundant (at least proximally), sometimes absent or nearly so (var. rupincola);

hypanthium 2–6 mm diam.;

sepals 3–6(–7) mm, apex long acuminate;

petals 4–6.5 × 4–6 mm;

filaments 1–3.5 mm, anthers 0.5–1 mm;

carpels 3–15, styles 1.5–2.1 mm.

Achenes

1.2 mm, ± to strongly rugose.

1.8–2.1 mm, smooth.

2n

= 28.

Potentilla pensylvanica

Potentilla effusa

Phenology Flowering summer.
Habitat Open prairies, steppe bluffs, shallow gravelly soil, rocky ridges and outcrops, dry stream channels, similar disturbed sites
Elevation 100–4000 m (300–13100 ft)
Distribution
from FNA
AK; AZ; CA; CO; IA; ID; MN; MT; ND; NE; NM; NV; SD; TX; UT; WY; AB; BC; MB; NT; ON; QC; SK; YT; Mexico (Tamaulipas); Eurasia
[WildflowerSearch map]
[BONAP county map]
from FNA
CO; ID; MN; MT; ND; NE; NM; SD; UT; WY; AB; MB; SK
[BONAP county map]
Discussion

Even in the reduced circumscription used here, Potentilla pensylvanica is exceptionally widespread, occurring in North America from Alaska to Hudson Bay, in the Great Plains and the North American Cordillera to northern Mexico. The species also grows across Siberia (where it has sometimes been called P. sibirica) and as isolated occurrences in the southwestern Alps and Spain (J. Soják 1987c; A. Kurtto et al. in J. Jalas et al. 1972+, vol. 13). One place P. pensylvanica does not occur is in Pennsylvania; the epithet was applied by Linnaeus to cultivated plants originating from Canada. Collections from Quebec are probably introductions (J. Cayouette, pers. comm.). The Oregon citation of P. pensylvanica (D. Mansfield 2000) refers to P. jepsonii.

Significant variation occurs within Potentilla pensylvanica, especially regarding vestiture and plant stature. J. Soják (1987c) has described several varieties, all Eurasian except var. brevipila (long hairs 0.6–1 mm); diminutive specimens from the Brooks Range of northern Alaska, isolated from other known populations of P. pensylvanica, have been described as P. brooksensis. Although much of the ecogeographic variation may merit recognition, at least at varietal level, doing so is postponed pending further analysis and clarification of nomenclature. Among the extremes are plants from the Great Plains, which have abundant long silky hairs overlying and obscuring the velvety layer of short hairs (resembling sympatric P. litoralis), and glabrate (except for glands) populations in Alaska. E. Hultén (1968) erroneously referred to the latter as P. pensylvanica var. glabrata (Lehmann) S. Watson; that name is a synonym of P. ovina var. ovina (sect. Multijugae). Most populations in Alaska also have larger than average flowers (petals to 7 × 7 mm, anthers ca. 1 mm).

Although Potentilla pensylvanica var. strigosa Pursh has been one of the most commonly used varieties in North America, the name has been effectively lectotypified by J. Soják (1987c) on a collection from Siberia. Soják identified this collection as the hybrid between P. pensylvanica and the Asian P. sanguisorba D. F. K. Schlechtendal; var. strigosa accordingly does not occur in North America.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Varieties 2 (2 in the flora).

In the southern Rocky Mountains, Potentilla effusa is relatively distinct from P. hippiana both morphologically and geographically, with P. effusa mostly east of the Continental Divide and P. hippiana mostly west. In general, P. hippiana differs from P. effusa in having leaflets more evenly paired, more tightly serrate with teeth often occurring on the whole margin, and more bicolored with abaxial vestiture of crisped rather than cottony hairs. Stems of P. effusa have more cauline leaves on average than P. hippiana, and vestiture of epicalyx bractlets of P. effusa (as here circumscribed) is never sericeous.

The distinction between the two species is marred by intermediate populations throughout their shared range in the northern Rocky Mountains and Great Plains. Most regional floras focused on these areas have accordingly included Potentilla effusa within P. hippiana, sometimes without infraspecific distinction. An alternate solution has been the recognition of P. hippiana subsp. effusa, with the subspecies further subdivided into the two varieties recognized here. The varieties themselves intergrade; P. effusa var. ×coloradensis (Rydberg) Th. Wolf is available for the hybrid.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Key
1. Leaflets gray to white, surfaces moderately long-hairy and moderately to densely cottony.
var. effusa
1. Leaflets ± green, surfaces glabrous or sparsely to moderately long-hairy (at least on veins) and not or sparsely cottony.
var. rupincola
Source FNA vol. 9, p. 214. FNA vol. 9, p. 162.
Parent taxa Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Pensylvanicae Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Leucophyllae
Sibling taxa
P. albiflora, P. ambigens, P. anachoretica, P. angelliae, P. anglica, P. anserina, P. arenosa, P. argentea, P. arizonica, P. basaltica, P. bicrenata, P. biennis, P. biflora, P. bimundorum, P. bipinnatifida, P. brevifolia, P. breweri, P. bruceae, P. brunnescens, P. canadensis, P. concinna, P. cottamii, P. crantzii, P. crebridens, P. crinita, P. cristae, P. demotica, P. drummondii, P. effusa, P. elegans, P. erecta, P. flabellifolia, P. fragiformis, P. furcata, P. glaucophylla, P. gracilis, P. grayi, P. hickmanii, P. hippiana, P. holmgrenii, P. hookeriana, P. hyparctica, P. inclinata, P. intermedia, P. jepsonii, P. johnstonii, P. lasiodonta, P. litoralis, P. macounii, P. millefolia, P. modesta, P. morefieldii, P. multijuga, P. multisecta, P. nana, P. newberryi, P. nivea, P. norvegica, P. ovina, P. paucijuga, P. pedersenii, P. plattensis, P. pseudosericea, P. pulchella, P. pulcherrima, P. recta, P. reptans, P. rhyolitica, P. rimicola, P. rivalis, P. robbinsiana, P. rubella, P. rubricaulis, P. sanguinea, P. saximontana, P. sierrae-blancae, P. simplex, P. sterilis, P. stipularis, P. subgorodkovii, P. subjuga, P. subvahliana, P. subviscosa, P. supina, P. thurberi, P. thuringiaca, P. tikhomirovii, P. townsendii, P. uliginosa, P. uschakovii, P. vahliana, P. verna, P. versicolor, P. villosa, P. villosula, P. vulcanicola, P. wheeleri
P. albiflora, P. ambigens, P. anachoretica, P. angelliae, P. anglica, P. anserina, P. arenosa, P. argentea, P. arizonica, P. basaltica, P. bicrenata, P. biennis, P. biflora, P. bimundorum, P. bipinnatifida, P. brevifolia, P. breweri, P. bruceae, P. brunnescens, P. canadensis, P. concinna, P. cottamii, P. crantzii, P. crebridens, P. crinita, P. cristae, P. demotica, P. drummondii, P. elegans, P. erecta, P. flabellifolia, P. fragiformis, P. furcata, P. glaucophylla, P. gracilis, P. grayi, P. hickmanii, P. hippiana, P. holmgrenii, P. hookeriana, P. hyparctica, P. inclinata, P. intermedia, P. jepsonii, P. johnstonii, P. lasiodonta, P. litoralis, P. macounii, P. millefolia, P. modesta, P. morefieldii, P. multijuga, P. multisecta, P. nana, P. newberryi, P. nivea, P. norvegica, P. ovina, P. paucijuga, P. pedersenii, P. pensylvanica, P. plattensis, P. pseudosericea, P. pulchella, P. pulcherrima, P. recta, P. reptans, P. rhyolitica, P. rimicola, P. rivalis, P. robbinsiana, P. rubella, P. rubricaulis, P. sanguinea, P. saximontana, P. sierrae-blancae, P. simplex, P. sterilis, P. stipularis, P. subgorodkovii, P. subjuga, P. subvahliana, P. subviscosa, P. supina, P. thurberi, P. thuringiaca, P. tikhomirovii, P. townsendii, P. uliginosa, P. uschakovii, P. vahliana, P. verna, P. versicolor, P. villosa, P. villosula, P. vulcanicola, P. wheeleri
Subordinate taxa
P. effusa var. effusa, P. effusa var. rupincola
Synonyms P. atrovirens, P. brooksensis, P. pensylvanica var. arida, P. pensylvanica var. brevipila, P. sibirica P. hippiana subsp. effusa, P. hippiana var. effusa
Name authority Linnaeus: Mant. Pl. 1: 76. (1767) Douglas ex Lehmann: Nov. Stirp. Pug. 2: 8. (1830)
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