Potentilla anserina
Potentilla versicolor
common silverweed, Pacific cinquefoil, silver weed cinquefoil, silverweed
Steens Mountain cinquefoil, varying cinquefoil
prostrate to ascending, (0.7–)1.5–2.5(–4) dm, lengths 2–4(–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).
pinnate with distal leaflets ± confluent, 4–12 × 1–2.5(–3.5) cm;
petiole 1–3 cm, straight hairs absent (on early-season petioles) or sparse to common, spreading-ascending to loosely appressed, 1–2 mm, soft, cottony hairs usually absent, glands sparse;
primary lateral leaflets 3–5 per side, on distal (1/3–)1/2–2/3 of leaf axis, overlapping, largest ones cuneate to flabellate, 0.5–1.5(–2) × 0.5–1.5 cm, distal 3/4 to whole margin unevenly incised 2/3 to completely to midvein (blade often medially split as well), ultimate teeth or segments 2–5(–8), ± oblanceolate, 3–11 × 1–3 mm, apical tufts to 1 mm, surfaces green to grayish green, not glaucous, straight hairs sparse to common (sparser adaxially), sometimes absent (except on margins), loosely appressed to ascending, 1–2 mm, soft, cottony hairs absent, glands sparse to common.
1–2(–3).
(1–)3–10-flowered, usually openly cymose.
1–3(–5) cm, straight to slightly recurved 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 lanceolate to elliptic, rarely ovate, 2–5 × 1–2 mm, sometimes apically toothed;
hypanthium 3–5 mm diam.;
sepals 4–7 mm, apex acute;
petals 4–7 × 3–5.5 mm;
filaments (1–)1.5–2.5 mm, anthers 0.5–0.8 mm;
carpels 10–25, styles 2 mm.
2 mm.
1.5–1.8 mm, smooth to faintly rugose, not carunculate.
Potentilla anserina
Potentilla versicolor
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.)
Potentilla versicolor is most common on Steens Mountain in Harney County, Oregon. Collections are known from other mountain ranges in eastern Oregon (some possibly representing distinct taxa) and from near Island Lake in the Ruby Mountains of northeastern Nevada. The species often grows and, apparently, intergrades with P. breweri; it is usually distinct in its lack of cottony hairs. Petals, filaments, and styles tend to be somewhat shorter in P. versicolor than in P. breweri. Collections of P. versicolor have most often been identified as P. breweri, P. millefolia, or P. ovina.
(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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