Potentilla argentea |
Potentilla gracilis |
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hoary cinquefoil, potentille argentée, silver cinquefoil, silver-leaf cinquefoil, silvery cinquefoil |
graceful cinquefoil, northwest cinquefoil, potentille grêle, slender cinquefoil |
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Glands | usually absent or inconspicuous, uncolored. |
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Stems | mostly decumbent to ascending, 1–6 dm. |
ascending to erect, (0.5–)2–7(–12) dm. |
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Basal leaves | palmate. |
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. |
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Cauline leaves | 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. |
1–4(–5). |
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Inflorescences | 10–80-flowered. |
(4–)10–50(–60)-flowered. |
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Pedicels | 0.3–1.5(–2) cm. |
0.3–3 cm. |
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Flowers | 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 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. |
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Achenes | 0.8–1.1 mm, smooth to lightly rugose. |
1–1.8 mm. |
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2n | = 14, 28, 35, 42, 56, 62 (Eurasia). |
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Potentilla argentea |
Potentilla gracilis |
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Phenology | Flowering spring–summer. | |||||||||||||||||
Habitat | Dry flats and slopes, roadsides, dry ditches, other open sites, in grasslands, oak and conifer woodlands | |||||||||||||||||
Elevation | 0–2000 m (0–6600 ft) | |||||||||||||||||
Distribution |
CO; CT; DC; IA; ID; IL; IN; KY; MA; MD; ME; MI; MN; MO; MT; NC; ND; NH; NJ; NY; OH; OR; PA; RI; SD; TN; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; NF; NS; ON; PE; QC; SK; SPM; Eurasia [Introduced in North America; introduced also in Pacific Islands (New Zealand)]
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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
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Discussion | 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.) |
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.) |
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Key |
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Source | FNA vol. 9, p. 144. | FNA vol. 9, p. 153. | ||||||||||||||||
Parent taxa | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Terminales | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Graciles | ||||||||||||||||
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Name authority | Linnaeus: Sp. Pl. 1: 497. (1753) | Douglas ex Hooker: Bot. Mag. 57: plate 2984. (1830) | ||||||||||||||||
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