Potentilla canadensis |
Potentilla biflora |
|
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dwarf cinquefoil |
two-flower cinquefoil |
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Stems | initially ascending to erect, soon becoming prostrate, flagelliform, not branched, eventually rooting at some nodes, (0.3–)0.5–12 dm. |
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Basal leaves | ± persistent, usually palmate, 2–9(–11) cm; petiole 1–7(–8) cm, long hairs abundant to dense, appressed to spreading, 1.5–3 mm, mostly ± weak, glands absent or sparse; leaflets (3–)5(–7), central mostly ± obovate to cuneate, sometimes narrowly so, (0.5–)1–4(–6) × (0.5–)0.8–2(–3) cm, distal 1/2 of margin incised 1/4–1/3 to midvein, teeth 2–7 per side, surfaces similar to ± dissimilar, abaxial green to silvery white, sparsely to densely hairy, adaxial green, sparsely to moderately hairy. |
petiole 1–4 cm, long hairs absent or sparse, 1.5–2 mm, crisped hairs absent or sparse; leaflet lobes linear, 10–20 × 1–2 mm, surfaces with long hairs sparse or absent. |
Cauline leaves | 0–1 proximal to 1st flowering node, not fully expanded at anthesis, usually palmate, 2–7(–9) cm; petiole (0.5–)1–6(–7.5) cm; leaflets (3–)5, ± resembling those of basal leaves, apex rounded to obtuse. |
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Inflorescences | solitary flowers at stolon nodes. |
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Pedicels | (1–)2–5(–9) cm. |
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Flowers | 5-merous; epicalyx bractlets linear to lanceolate-elliptic, (2–)3–5(–6) × 0.8–1.5 mm, slightly smaller than to ± equal to sepals; hypanthium 2.5–5 mm diam.; sepals (2–)3–5(–6) mm, apex acute; petals 4–6(–8) × 3.5–6.5(–8) mm, apex rounded to slightly retuse; stamens ca. 20, filaments 0.5–2 mm, anthers 0.4–1 mm; carpels 20–40, styles 0.8–1.4 mm. |
epicalyx bractlets oblong, ovate, or lanceolate, 2.5–4 × 0.4–1.3 mm; sepals 3.5–5 mm, apex acute to apiculate; petals 6–10 × 4–10 mm; filaments 2.8–4 mm, anthers 0.6 mm; carpels 15–25. |
Achenes | 1.2–1.4 mm, smooth. |
1.5–2 mm. |
Rootstocks | erect, stout, 0.5–2 cm. |
|
2n | = 28. |
= 14. |
Potentilla canadensis |
Potentilla biflora |
|
Phenology | Flowering late Mar–early Jun. | Flowering summer. |
Habitat | Dry flats and slopes in lawns, pastures, roadsides, cherty slopes, dry meadows, edges of oak and conifer woodlands, often on acidic soil | Dryas fellfields, gravel terraces, well-drained soil, often with seasonal seepage, on calcareous substrates |
Elevation | 0–1500 m (0–4900 ft) | 0–2000 m (0–6600 ft) |
Distribution |
CT; DC; DE; KY; MA; MD; ME; MO; NC; NH; NJ; NY; OH; PA; RI; SC; TN; VA; VT; WV; NS; ON
|
AK; BC; NT; NU; YT; Asia |
Discussion | A cream-colored form (ochroleuca) was described from a now-obliterated site in Massachusetts (M. L. Fernald 1931). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
In North America, Potentilla biflora is mostly Beringian, barely reaching northern British Columbia and western Northwest Territories, with one locality in Nunavut (southern Victoria Island). The amphi-Beringian range is strongly isolated from other Asian populations, the closest being in the Altai Mountains of south-central Siberia. Two varieties are accepted in China (Li C. L. et al. 2003c), with North American plants falling in var. biflora. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 9, p. 134. | FNA vol. 9, p. 131. |
Parent taxa | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Potentilla | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Biflorae |
Sibling taxa | ||
Synonyms | P. canadensis var. pumila, P. canadensis var. villosissima, P. caroliniana, P. pumila | |
Name authority | Linnaeus: Sp. Pl. 1: 498. (1753) | D. F. K. Schlechtendal: Ges. Naturf. Freunde Berlin Mag. Neuesten Entdeck. Gesammten Naturk. 7: 297. (1816) |
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