Potentilla anserina

Linnaeus

Sp. Pl. 1: 495. 1753.

Common names: Silverweed
Illustrated
Synonyms: Argentina anserina (Linnaeus) Rydberg
Treatment appears in FNA Volume 9. Treatment on page 127. Mentioned on page 122.

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). 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). Achenes 2 mm.

Distribution

V9 181-distribution-map.jpg

Alta., B.C., Man., N.B., N.S., N.W.T., Nfld. and Labr., Nunavut, Ont., P.E.I., Que., Sask., Yukon, Alaska, Ariz., Calif., Colo., Conn., Idaho, Ill., Ind., Iowa, Maine, Mass., Mich., Minn., Mont., N.Dak., N.H., N.Mex., N.Y., Nebr., Nev., Ohio, Oreg., R.I., S.Dak., Utah, Vt., Wash., Wis., Wyo., Mexico, South America (Argentina), South America (Chile), Eurasia, Pacific Islands (New Guinea), Pacific Islands (New Zealand), s Australia

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.

Selected References

None.

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. Potentilla anserina 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. Potentilla anserina 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. Potentilla anserina 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. Potentilla anserina subsp. groenlandica

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... more about "Potentilla anserina"
0.2 cm2 mm <br />0.002 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
papillate +  and rugose +
green +  and white +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.13 cm1.3 mm <br />0.0013 m <br />) +
subacute;acuminate +
Reidar Elven +  and David F. Murray +
Linnaeus +
compound +  and simple +
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 +
Silverweed +
Alta. +, B.C. +, Man. +, N.B. +, N.S. +, N.W.T. +, Nfld. and Labr. +, Nunavut +, Ont. +, P.E.I. +, Que. +, Sask. +, Yukon +, Alaska +, Ariz. +, Calif. +, Colo. +, Conn. +, Idaho +, Ill. +, Ind. +, Iowa +, Maine +, Mass. +, Mich. +, Minn. +, Mont. +, N.Dak. +, N.H. +, N.Mex. +, N.Y. +, Nebr. +, Nev. +, Ohio +, Oreg. +, R.I. +, S.Dak. +, Utah +, Vt. +, Wash. +, Wis. +, Wyo. +, Mexico +, South America (Argentina) +, South America (Chile) +, Eurasia +, Pacific Islands (New Guinea) +, Pacific Islands (New Zealand) +  and s Australia +
not +  and aggregated +
0.7 cm7 mm <br />0.007 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
dentate +, 2-fid +  and ovate-triangular +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.45 cm4.5 mm <br />0.0045 m <br />) +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.35 cm3.5 mm <br />0.0035 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 />) +
stoloniferous +  and short-rhizomatous +
straight +
cottony +  and crisped-cottony +
sparse +  and common +
cottony-crisped +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.35 cm3.5 mm <br />0.0035 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 /> (0.7 cm7 mm <br />0.007 m <br />) +
0.5mm;2.5mm +
turbinate +, patelliform +  and cupulate +
racemiform open +  and more or less congested +
crassinucellate +
5 cm50 mm <br />0.05 m <br /> (7 cm70 mm <br />0.07 m <br />) +
2 cm20 mm <br />0.02 m <br /> (3 cm30 mm <br />0.03 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (5 cm50 mm <br />0.05 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (2 cm20 mm <br />0.02 m <br />) +
bipinnate +, odd-pinnate +, subpalmate +, palmate +  and ternate +
opposite +  and alternate +
marcescent +
well-developed +
persistent +
cauline +  and basal +
reduced +
not +  and overlapping +
elliptic +  and obovate +
linear +  and oblanceolate +
palmate +  and pinnate +
1/4 (?) +  and 1/2 (?) +
incised +, flat +  and revolute +
inferior +  and superior +
clustered +, biseriate +  and superposed +
45 cm450 mm <br />0.45 m <br /> (55 cm550 mm <br />0.55 m <br />) +
2 cm20 mm <br />0.02 m <br /> (45 cm450 mm <br />0.45 m <br />) +
elliptic +  and broadly elliptic +
1.5 cm15 mm <br />0.015 m <br /> (2 cm20 mm <br />0.02 m <br />) +
1.5 cm15 mm <br />0.015 m <br /> (2 cm20 mm <br />0.02 m <br />) +
1 cm10 mm <br />0.01 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
bright-yellow +
free +  and distinct +
5mm;15mm +
commonly obcordate;nearly round +
0.5 cm5 mm <br />0.005 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (1 cm10 mm <br />0.01 m <br />) +
15 cm150 mm <br />0.15 m <br /> (25 cm250 mm <br />0.25 m <br />) +
1 cm10 mm <br />0.01 m <br /> (15 cm150 mm <br />0.15 m <br />) +
adnate +, free +, connate +  and distinct +
50 cm500 mm <br />0.5 m <br /> (75 cm750 mm <br />0.75 m <br />) +
3 cm30 mm <br />0.03 m <br /> (50 cm500 mm <br />0.5 m <br />) +
not arillate +
0.7 cm7 mm <br />0.007 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
persistent +
free +  and distinct +
erect +  and spreading +
lanceolate +  and broadly ovate or deltate +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
Illustrated +
free +  and distinct +
reddish +  and green +
prostrate +  and erect +
lateral;more or less persistent basal +
1 +  and many +
flagelliform +
palmate +  and pinnate +
linear;ovate +
deciduous +
distinct +
papillate-swollen +  and columnar-filiform +
rough-thickened +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
Argentina anserina +
not fleshy-thickened +
Potentilla anserina +
Potentilla sect. Pentaphylloides +
species +
5 (?) +  and 12 (?) +
inconspicuous +
enlarged +
biennial +, annual +  and perennial +
herb +  and matted +