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common silverweed, Pacific cinquefoil, silver weed cinquefoil, silverweed

graceful cinquefoil, northwest cinquefoil, potentille grêle, slender cinquefoil

Glands

usually absent or inconspicuous, uncolored.

Stems

ascending to erect, (0.5–)2–7(–12) dm.

Basal leaves

petiole (0.5–)1–15(–25) cm, long hairs absent or sparse to dense, 1.5–3.5 mm;

larger leaflets (0.4–)0.5–5(–7) × (0.2–)0.3–2(–3) cm, surfaces: abaxial with long hairs absent or sparse to abundant, not restricted to veins, 0.5–2(–2.5) mm, cottony-crisped hairs usually dense or usually absent (in subsp. groenlandica), adaxial with long hairs absent or sparse to abundant, cottony-crisped hairs usually absent, sometimes sparse to common (especially subsp. yukonensis).

usually not in ranks, palmate, rarely subpalmate, 4–40(–55) cm;

petiole (2–)3–25(–45) cm, long hairs sparse to dense, appressed to spreading, 0.5–2(–3) mm, weak to stiff, short hairs absent, crisped hairs usually absent, cottony hairs absent or sparse to abundant (var. owyheensis), glands absent or sparse;

leaflets 5–9, on tip, rarely less than distal 1/10, of leaf axis, separate to overlapping, largest ones oblanceolate to elliptic or obovate, (1.5–)2–9(–11) × (0.7–)1.5–4 cm, margins flat to revolute, distal (2/3–)3/4 to nearly whole length evenly to unevenly incised 1/4–3/4+ to midvein, undivided medial blade 2–20 mm wide, teeth (4–)6–10(–11) per side (sometimes secondarily toothed), linear to broadly lanceolate, 2–20(–35) mm, surfaces ± similar to strongly dissimilar, abaxial green or pale green to white, usually not glaucous, long hairs sparse to abundant (sometimes mostly on veins), short-crisped hairs absent or sparse to abundant, cottony hairs absent or sparse to dense, glands usually absent or obscured to sparse, sometimes common, adaxial dark green to grayish, long hairs sparse to ± abundant, rarely absent or dense, short-crisped hairs absent or sparse, cottony hairs absent or sparse to abundant (var. owyheensis), glands usually absent or sparse to sometimes common.

Cauline leaves

1–4(–5).

Inflorescences

(4–)10–50(–60)-flowered.

Pedicels

0.3–3 cm.

Flowers

epicalyx bractlets narrowly to broadly ovate-triangular or linear to elliptic, (2–)2.5–7(–8) × (0.3–)0.5–3(–3.5) mm, often 2-fid or dentate;

sepals (3–)3.5–7(–9) mm, apex subacute to acuminate;

petals (4–)5–15(–20) × (2.5–)3–10(–12) mm;

filaments (1–)2.5–3.5(–4.5) mm, anthers 0.7–1.3 mm;

carpels (10–)20–200(–250).

epicalyx bractlets linear to narrowly lanceolate or elliptic, 2–6(–8) × 0.5–1.5(–2.5) mm, hairs sparse to abundant, rarely dense, ± appressed to ascending, rarely spreading, glands usually absent or inconspicuous;

hypanthium 3.5–6 mm diam.;

sepals 4–8(–10) mm, apex acute to long acuminate;

petals (3–)4–10(–11) × (3–)4–10(–12) mm;

filaments (1–)1.5–2.5(–3.5) mm, anthers 0.6–1.2(–1.6) mm;

carpels (15–)20–50, styles ± tapered, papillate-swollen proximally, (1–)1.5–2.5(–3) mm.

Achenes

2 mm.

1–1.8 mm.

Potentilla anserina

Potentilla gracilis

Distribution
from FNA
AK; AZ; CA; CO; CT; IA; ID; IL; IN; MA; ME; MI; MN; MT; ND; NE; NH; NM; NV; NY; OH; OR; RI; SD; UT; VT; WA; WI; WY; AB; BC; MB; NB; NL; NS; NT; NU; ON; PE; QC; SK; YT; Mexico; South America (Argentina, Chile); Eurasia; Pacific Islands (New Guinea, New Zealand); s Australia
[WildflowerSearch map]
[BONAP county map]
from FNA
AK; AZ; CA; CO; ID; MI; MN; MT; ND; NV; OR; SD; UT; WA; WI; WY; AB; BC; MB; NT; ON; PE; QC; SK; YT
[WildflowerSearch map]
[BONAP county map]
Discussion

Subspecies 4 or 5 (4 in the flora).

Potentilla anserina is polymorphic in most features, especially in hairiness, but also in size and in degree of dissection of leaflets, epicalyx bractlets, and sepals. While most of the variation described by A. G. Blytt (1906) is taxonomically insignificant, A. Rousi (1965) found support for three northern races: subspp. anserina, egedei, and pacifica. He also suggested that P. yukonensis Hultén might qualify as a separate subspecies. This treatment follows J. Soják (1994) in accepting four northern subspecies of P. anserina, all present in North America.

A. Rousi (1965) demonstrated partial interfertility between the races of Potentilla anserina, which form intermediates in all zones of contact. The distinctness of the four races, in spite of intermediates, is upheld by being partly allopatric and occupying different habitats where they are sympatric. As partly interfertile parapatric entities, they are best treated as subspecies.

The vast majority of chromosome counts are tetraploid. Tetraploid plants (2n = 28) are fully fertile; hexaploids (2n = 42) are largely pollen and seed sterile; pentaploids (2n = 35) are probably occasional hybrids (S. Erlandsson 1942, 1942b; A. Rousi 1965). A. Kurtto et al. (in J. Jalas et al. 1972+, vol. 13) considered numbers above tetraploid level as cases of occasional autopolyploidy.

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

Varieties 5 (5 in the flora).

Because variation within Potentilla gracilis and other members of sect. Graciles is still far from resolved, taxonomic recognition is given to only the most distinctive extremes and that mostly at the varietal level. The goal is to call attention to areas that need study rather than to provide a full resolution, and even this leaves out some large, widespread populations in both keys and descriptions. The taxonomic placement of some available names, such as P. glomerata A. Nelson, P. longipedunculata Rydberg, and P. macropetala Rydberg, likewise remains unresolved.

The vouchers for the report by M. L. Fernald (1950) of Potentilla gracilis and P. pulcherrima from New Hampshire are presumably specimens collected in Coos County by A. S. Pease (NEBC). The three collections differ from one another, corresponding most closely to var. fastigiata, var. flabelliformis, and P. pulcherrima. The presence of such diversity in the same meadow, all as disjunct occurrences, suggests an artificial, non-persisting introduction.

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

Key
1. Epicalyx bractlets equal to or longer than sepals, often 2-fid or dentate; leaflet surfaces: abaxial with cottony-crisped hairs dense, long hairs common to abundant, on and between veins, adaxial glabrous or sparsely to densely hairy; achenes with dorsal groove; inland and seashore plants
→ 2
1. Epicalyx bractlets shorter than sepals, usually entire, rarely 2-fid or dentate; leaflet surfaces: abaxial with cottony-crisped hairs absent or sparse to dense, long hairs absent or sparse, on veins, adaxial usually glabrous, rarely sparsely to densely hairy; achenes without dorsal groove; seashore or near-coastal plants
→ 3
2. Hypanthium patelliform (wider than deep) in fruit; epicalyx bractlets narrowly to broadly ovate-triangular, equal to sepals; most of North America.
subsp. anserina
2. Hypanthium turbinate (± as deep as wide) in fruit; epicalyx bractlets usually linear to elliptic, longer than sepals, rarely subequal; interior w Canada and Alaska.
subsp. yukonensis
3. Carpels (20–)50–200(–250); leaves (3–)10–50(–75) cm; leaflets (4–)5–10(–15) per side, abaxial surfaces densely hairy, teeth (4–)6–12(–16) per side, teeth apices acute to acuminate, rarely subacute; flowers 1–2.5(–3.5) cm diam.
subsp. pacifica
3. Carpels 25–60; leaves (1–)2–10 cm, rarely longer; leaflets 2–4(–5) per side, abaxial surfaces glabrous, sometimes sparsely to densely hairy, teeth 2–6(–10) per side, teeth apices rounded to subacute; flowers 0.8–1.5 cm diam.
subsp. groenlandica
1. Petioles: cottony hairs usually abundant, rarely sparse.
var. owyheensis
1. Petioles: cottony hairs usually absent
→ 2
2. Leaflets incised 1/4–1/2 to midvein, undivided medial blade 5–20 mm wide, teeth narrowly lanceolate to ovate
→ 3
2. Leaflets incised 3/4+ to midvein, undivided medial blade 2–6 mm wide, teeth linear
→ 4
3. Leaflet surfaces usually strongly dissimilar, abaxial white, sometimes grayish, crisped-cottony hairs abundant to dense, rarely sparse, adaxial green; near coastal n California to Alaska.
var. gracilis
3. Leaflet surfaces ± similar to ± dissimilar, abaxial pale green to greenish gray, crisped hairs absent or sparse to abundant, cottony hairs usually absent, adaxial green to grayish green; widespread.
var. fastigiata
4. Leaflet surfaces usually ± dissimilar, abaxial grayish to whitish, long hairs abundant to dense, crisped hairs sparse to abundant, cottony hairs usually absent, adaxial green to grayish green, teeth 3–13(–20) mm, not secondarily toothed; petioles 2–15(–25) cm.
var. elmeri
4. Leaflet surfaces strongly dissimilar, abaxial white, long hairs sparse to common (mostly on veins), cottony or crisped-cottony hairs dense, straight hairs dense, mostly on veins, adaxial usually dark green, sometimes grayish green, teeth (8–)10–20(–35) mm, often secondarily toothed; petioles (7–)10–25(–30) cm.
var. flabelliformis
Source FNA vol. 9, p. 127. FNA vol. 9, p. 153.
Parent taxa Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Pentaphylloides Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Graciles
Sibling taxa
P. albiflora, P. ambigens, P. anachoretica, P. angelliae, P. anglica, 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. 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
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. 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. anserina subsp. anserina, P. anserina subsp. groenlandica, P. anserina subsp. pacifica, P. anserina subsp. yukonensis
P. gracilis var. elmeri, P. gracilis var. fastigiata, P. gracilis var. flabelliformis, P. gracilis var. gracilis, P. gracilis var. owyheensis
Synonyms Argentina anserina
Name authority Linnaeus: Sp. Pl. 1: 495. (1753) Douglas ex Hooker: Bot. Mag. 57: plate 2984. (1830)
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