Potentilla ovina |
Potentilla nana |
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sheep cinquefoil |
arctic cinquefoil, dwarf cinquefoil |
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Habit | Plants rosetted to ± matted; taproots sometimes ± fleshy-thickened. | Plants densely tufted; caudex branches short, slender to ± stout, diam. 0.5–1 cm, including old leaf bases. | ||||
Stems | prostrate to ascending, (0.3–)0.8–2(–3.5) dm, lengths (1–)1.5–3 times basal leaves. |
ascending to erect, 0.1–0.5(–0.7) dm, lengths 1–2 times basal leaves. |
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Basal leaves | pinnate with distal leaflets ± distinct, (1.5–)2–10(–13) × 0.7–3.5(–5) cm; petiole 0.5–3.5(–5) cm, straight hairs sparse to abundant, sometimes absent (var. decurrens), ± appressed to ascending, 1 mm, ± stiff, cottony hairs absent, glands sparse, often obscured; primary lateral leaflets 3–6 per side (often with additional interspersed leaflets), on distal 1/2–2/3(–3/4) of leaf axis, ± separate to ± overlapping, largest ones narrowly cuneate-oblanceolate to ± obovate, (0.3–)0.5–2(–3.5) × (0.2–)0.3–0.8(–1) cm, distal 1/4 to whole margin unevenly to pinnately (at least distal leaflets of var. ovina) incised 1/2–3/4+ to midvein, ultimate teeth 2–9(–11), linear or oblong to ovate, 1–7(–9) × 1–2 mm, apical tufts 0.5–2 mm, surfaces green to grayish, not glaucous, straight hairs sparse to abundant (sparser adaxially), sometimes absent (except on margins), loosely appressed, 0.5–2 mm, ± stiff, cottony hairs absent, crisped hairs sometimes sparse to common, glands absent or inconspicuous. |
not in ranks, ternate, 1–5 cm; stipules: apex acute; petiole 0.5–3.5 cm, long hairs sparse to abundant, ascending to spreading, 0.5–2 mm, ± soft, glands sparse to common; leaflets 3, central obovate, 0.5–2 × 0.5–1 cm, petiolule 0–1 mm, margins revolute, not lobed, distal 1/2–2/3 evenly incised ± 1/2 to midvein, teeth 3–4(–6) per side, surfaces ± similar, green (paler abaxially), hairs sparse to abundant, 0.8–1.2 mm, glands sparse to common. |
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Cauline leaves | 1–2. |
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Inflorescences | (1–)2–11(–20)-flowered, usually openly cymose. |
1(–2)-flowered. |
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Pedicels | (0.8–)1–2(–4) cm, straight to ± recurved in fruit. |
straight, 0.2–1.5 cm in flower, to 5 cm in fruit. |
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Flowers | epicalyx bractlets linear-lanceolate to narrowly elliptic, sometimes doubled, 2–3.5(–5) × 1 mm; hypanthium 3–5 mm diam.; sepals 3.5–5.5(–7) mm, apex acute to obtuse; petals 4–7(–8) × 3.5–8 mm; filaments 1–2.5 mm, anthers 0.4–1 mm usually ± 1/2 as long as filaments; carpels 10–20, styles 2–3 mm. |
epicalyx bractlets oblong or ovate, 2.5–5 × 1.5–3.5 mm, margins revolute; hypanthium 3–3.5 mm diam.; sepals 2.5–5 mm, apex ± acute; petals pale yellow, 4–8 × 4–6 mm; filaments 1.2–2 mm, anthers 0.3–0.4 mm; carpels 40–50, styles ± columnar, not or scarcely papillate-swollen proximally, 0.8–1.2 mm. |
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Achenes | 1.5–2 mm, smooth, not carunculate. |
1.4–1.6 mm. |
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Potentilla ovina |
Potentilla nana |
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Phenology | Flowering summer. | |||||
Habitat | Alpine and coastal Dryas-Salix-Empetrum heaths, gravelly slopes, ridge crests, fellfields, scree and talus | |||||
Elevation | 100–1100 m (300–3600 ft) | |||||
Distribution |
CO; ID; MT; NV; OR; UT; WY; AB; BC
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AK; BC
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Discussion | Varieties 2 (2 in the flora). Potentilla ovina is here accepted as an implicit new name by J. M. Macoun for P. diversifolia var. pinnatisecta, in agreement with N. H. Holmgren (1997b). In contrast, B. C. Johnston (1980) considered the names heterotypic. Potentilla ovina has priority at the species rank over P. pinnatisecta by one month. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Potentilla nana has most often been considered a race of P. hyparctica or as the priority name for P. hyparctica. As now defined, P. nana occurs in an arc across southern Alaska, from the Aleutian and Pribilof islands to the Alaskan panhandle and adjacent British Columbia. T. Wolf (1908) treated it as a dwarf form of P. fragiformis; J. Soják (1996) interpreted P. nana as a hybrid species originating from cross(es) between P. fragiformis and P. hyparctica. Although the hybrid hypothesis has morphologic support, P. nana has a unique combination of morphologic features and has a distinct range from both P. fragiformis and P. hyparctica. The species are also ecologically segregated: P. nana is a coastal heath and gravel slope species, like P. hyparctica; P. fragiformis is strictly maritime coastal. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 9, p. 171. | FNA vol. 9, p. 192. | ||||
Parent taxa | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Multijugae | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Aureae | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | P. diversifolia var. pinnatisecta, P. pinnatisecta, P. plattensis var. pinnatisecta | P. emarginata subsp. nana | ||||
Name authority | J. M. Macoun: Canad. Rec. Sci. 6: 464. (1896) | D. F. K. Schlechtendal: Ges. Naturf. Freunde Berlin Mag. Neuesten Entdeck. Gesammten Naturk. 7: 296. (1816) | ||||
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