Potentilla argentea
Potentilla vulcanicola
hoary cinquefoil, potentille argentée, silver cinquefoil, silver-leaf cinquefoil, silvery cinquefoil
stout, sometimes ± columnar, not sheathed with marcescent whole leaves.
mostly decumbent to ascending, 1–6 dm.
ascending to erect, (0.2–)0.4–1.6(–2) dm, lengths 2–3 times basal leaves.
palmate.
1–6(–11) cm;
petiole 0.5–4(–9) cm, long hairs ± abundant, ascending to spreading, sometimes loosely appressed, 1–2.5 mm, soft to weak, smooth, crisped(/cottony) hairs absent or sparse, sometimes common, glands absent or sparse;
leaflets overlapping, central broadly obovate, 0.8–2(–2.5) × 0.8–1.5(–2.5) cm, sessile or subsessile, base broadly cuneate, margins strongly revolute, distal 1/2–2/3 incised ± 1/2 to midvein, teeth 2–3(–4) per side, distant, surfaces strongly dissimilar, abaxial grayish white, long hairs 1–2 mm, cottony-crisped hairs ± dense, adaxial usually dark green, sometimes grayish green, long hairs sparse to abundant, other hairs usually absent.
2–9, proximal ones 2–7(–10) cm;
proximal petioles 1–4(–7) cm, long hairs absent or sparse, ± ascending, 1–2 mm, soft, short and crisped hairs absent or obscured, cottony hairs dense, glands absent or obscured;
leaflets 5(–7), central one ± oblanceolate, (0.5–)1–3 × 0.3–1(–1.3) cm, margins revolute, distal 1/2–2/3 evenly or unevenly incised 1/2–3/4+ to midvein, teeth 2–3 per side (more if lobed or secondarily toothed), surfaces strongly dissimilar, abaxial white, long hairs ± sparse (mostly on veins), 1–2 mm, weak, short and crisped hairs absent or obscured, cottony hairs dense, glands absent or obscured, adaxial long hairs absent or sparse to common, short or crisped hairs absent or sparse, cottony hairs absent, glands absent or sparse.
(0–)1–2(–3).
10–80-flowered.
1–2(–5)-flowered.
0.3–1.5(–2) cm.
1–2 cm in flower, to 5 cm in fruit.
epicalyx bractlets oblong to narrowly ovate, 1.5–3 × 0.7–1.2 mm, lengths 2/3–1 times sepals;
sepals 2–4.5 mm, apex ± acute;
petals (2–)2.5–4 × 1.5–3 mm;
filaments 0.8–1.5 mm, anthers 0.3–0.6(–0.8) mm;
carpels 30–60, styles 0.6–0.9 mm, often strongly papillate-swollen proximally.
epicalyx bractlets ± oblong to ovate, 4–8(–10) × 1.8–3(–5) mm, 2/3 to as wide as sepals, margins revolute, sometimes flat, red glands absent;
hypanthium 3.5–4.5 mm diam.;
sepals 5–8 mm, apex ± acute;
petals 7–9 × 7–10 mm, longer than sepals;
filaments 0.8–1 mm, anthers 0.6–0.7 mm;
carpels 20–30, apical hairs sparse to abundant (straight), styles conic-columnar, ± papillate-swollen in less than proximal 1/5, or sometimes to 1/5, 0.8–1.1 mm.
0.8–1.1 mm, smooth to lightly rugose.
0.9–1.2 mm.
= 14, 28, 35, 42, 56, 62 (Eurasia).
= 28 (Russian Far East).
Potentilla argentea
Potentilla vulcanicola
The bright, silvery vestiture of the leaves quickly distinguishes Potentilla argentea from P. inclinata and P. intermedia. Although treated here as introduced, some (P. A. Rydberg 1898; P. A. Werner and J. D. Soule 1976) considered P. argentea to be probably native in eastern North America.
The Potentilla argentea species group is an amphi- or apomictic polyploid complex that has been the subject of numerous cytological, sexual, and molecular studies (for example, A. Müntzing and G. Müntzing 1945; A. Müntzing 1958; J. Paule et al. 2011). Taxonomic treatments have ranged from a highly polymorphic single species to an abundance of species, varieties, and forms (T. Wolf 1908). This treatment is at the conservative end of the spectrum. Some New England references (R. C. Bean et al. 1967; F. C. Seymour 1969) distinguish plants with densely white-hairy adaxial leaflet surfaces as var. pseudocalabra Th. Wolf, a name based on plants from southeastern Europe. Molecular analysis by Paule et al. supports the conclusion by Wolf that the variety consists of intermediates between P. argentea and P. calabra Tenore. The optimum taxonomic disposition of var. pseudocalabra, and whether any North American plants are properly included, remains to be determined.
Potentilla argentea has been reported as an active agent in treating cirrhosis of the liver (N. T. Starostenko and V. N. Starostenko 1971).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Potentilla vulcanicola is close morphologically to P. uniflora in the narrow sense and largely replaces it in southern and eastern Chukotka, Alaska, and northwestern Canada, where it reaches east of Mackenzie River on the coastal mainland and the westernmost islands (Banks and Victoria islands). Potentilla subgorodkovii and P. vulcanicola account for a major part of North American records of P. uniflora.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
- Local floras:
BC, 
OR, 
WA - Local Web sites:
Flora NW, 
Go Botany, 
IL Wildflowers, 
MD Biodiversity, 
MI Flora, 
MN Wildflowers, 
MO Plants, 
PNW Herbaria 
WildflowerSearch
iNaturalist (observations)
USDA Plants Database- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
