Potentilla anserina
Potentilla subgorodkovii
common silverweed, Pacific cinquefoil, silver weed cinquefoil, silverweed
Beringian cinquefoil, yurtsev's cinquefoil
stout, usually columnar, sometimes sheathed with marcescent whole leaves.
erect, (0.2–)0.3–1.5(–2) dm, lengths 1.5–2.5(–3.5) times 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).
(1–)2–10(–15) cm;
petiole (0.5–)1–5(–12) cm, long hairs common to dense, ± ascending to loosely appressed, sometimes spreading, 1–2 mm, ± soft, smooth, crisped/short-cottony hairs usually sparse, sometimes absent or common, glands absent, sparse, or obscured;
leaflets separate to slightly overlapping, central obovate or obtriangular, (0.5–)1–2(–3) × (0.4–)0.8–1.5(–2) cm, sessile or subsessile, base cuneate, margins revolute, distal (1/3–)1/2–2/3(–3/4) incised 1/2–2/3(–3/4) to midvein, teeth 2–3(–4) per side, usually ± distant, surfaces somewhat to more often strongly dissimilar, abaxial yellowish or grayish white to white, long hairs 0.8–1.5 mm, cottony-crisped hairs ± dense, adaxial green to grayish green, long hairs sparse to ± abundant, other hairs usually absent.
(0–)1(–2).
usually 1(–2)-flowered, rarely to 5-flowered.
(0.5–)2–4 cm in flower, to 5 cm in fruit.
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 elliptic-lanceolate to ovate, (3–)4–6(–7) × (0.8–)1.2–2(–2.5) mm, (1/2–)2/3 to as wide as sepals, margins revolute, rarely flat, red glands absent;
hypanthium 2.5–4 mm diam.;
sepals 4–6(–7) mm, apex subacute;
petals (5–)6–9 × (5–)7–9 mm, significantly longer than sepals;
filaments 1–1.3 mm, anthers 0.4–0.6 mm;
carpels 30–40, apical hairs absent, styles narrowly columnar to conic-tapered, papillate-swollen on proximal 1/5(–1/3), 0.9–1.1 mm.
2 mm.
1.2–2 mm.
= 28, 42, 49, 56 (Russian Far East).
Potentilla anserina
Potentilla subgorodkovii
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.)
The name Potentilla subgorodkovii was coined for a presumed hybrid species resulting from P. crebridens × P. subvahliana; here it is applied in a collective meaning for plants combining characteristics from multiple species of the P. uniflora/villosa and P. nivea groups. Morphologically, this collective entity is much closer to the P. uniflora/villosa group than to the P. nivea group and is clearly different from primary hybrids and clones, which are often observed.
Potentilla subgorodkovii constitutes about half of what previously has been considered P. uniflora in Alaska and Yukon and is the only such entity fully confirmed south of northern British Columbia. These southern populations occur outside the range of possible parental members of the P. uniflora/villosa group and do not support the hybrid hypothesis. They may instead represent a distinct species, not yet described.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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 |
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- Local floras: BC
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- WildflowerSearch
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- Plants of the World Online
- Encyclopedia of Life
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