Potentilla canadensis |
Potentilla subvahliana |
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dwarf cinquefoil |
high arctic cinquefoil |
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Habit | Plants usually cushion-forming. | |
Caudex branches | stout, columnar, sheathed with marcescent whole leaves. |
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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. |
erect, 0.2–0.6(–1.1) dm, lengths 2–4 times basal leaves. |
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. |
0.5–2.5(–3) cm; petiole 0.3–1.5(–2) cm, long hairs common to abundant, spreading to ascending, 1(–2) mm, ± weak, rarely stiff, smooth, crisped/short-cottony hairs usually absent, sometimes sparse, glands sparse to common; leaflets separate to slightly overlapping, central obovate, 0.5–1.2(–1.5) × 0.4–0.9(–1) cm, subsessile to short-petiolulate, base cuneate, margins revolute, distal 1/2 incised 1/2–3/4 to midvein, teeth (1–)2–3(–4) per side, ± distant, surfaces ± dissimilar, abaxial grayish or yellowish white, long hairs 0.5–1 mm, cottony-crisped hairs ± dense (often obscured by long hairs), adaxial dark green to greenish gray, long hairs ± abundant, other hairs 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. |
(0–)1(–2). |
Inflorescences | solitary flowers at stolon nodes. |
1(–2)-flowered. |
Pedicels | (1–)2–5(–9) cm. |
1–2(–3) cm in flower, to 5.5 cm in fruit. |
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 lanceolate to elliptic-ovate, rarely linear, 3–6(–7) × 0.8–2(–2.3) mm, (1/2–)2/3 to nearly as wide as sepals, margins flat or ± revolute, red glands absent; hypanthium 2.5–4 mm diam.; sepals 3–5(–6) mm, apex obtuse to subacute; petals 4–8(–9) × 4–9 mm, longer than sepals; filaments 1–1.3 mm, anthers 0.3–0.5 mm; carpels 25–35, apical hairs absent, styles conic-columnar, ± papillate-swollen on less than proximal 1/5, 0.9–1.1 mm. |
Achenes | 1.2–1.4 mm, smooth. |
1.2–1.6 mm. |
Rootstocks | erect, stout, 0.5–2 cm. |
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2n | = 28. |
= 28 (Russian Far East). |
Potentilla canadensis |
Potentilla subvahliana |
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Phenology | Flowering late Mar–early Jun. | Flowering late spring to summer. |
Habitat | Dry flats and slopes in lawns, pastures, roadsides, cherty slopes, dry meadows, edges of oak and conifer woodlands, often on acidic soil | Rocky alpine heaths, rock outcrops and crevices, scree and talus, dry tundra, coastal bluffs, stabilized sand dunes, usually on calcareous bedrock |
Elevation | 0–1500 m (0–4900 ft) | 0–1700 m (0–5600 ft) |
Distribution |
CT; DC; DE; KY; MA; MD; ME; MO; NC; NH; NJ; NY; OH; PA; RI; SC; TN; VA; VT; WV; NS; ON
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AK; AB; BC; NT; NU; QC; YT; Greenland; e Asia (Russian Far East) |
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.) |
The major part of the range assigned to Potentilla vahliana by E. Hultén (1968) belongs to P. subvahliana. Two morphologic types are present within what is accepted here as Potentilla subvahliana. Plants corresponding to the type of P. subvahliana (Wrangel Island) are widespread throughout northeastern Asia (Chukotka) and arctic North America to northwestern Greenland. Some plants in alpine Alaska, Yukon, and east to Amundsen Gulf, Nunavut, are redder, more densely columnar, and less hairy, with smaller leaves having fewer and narrower lobes, more slender one-flowered stems, narrow and entire bracts, narrower sepals, and much narrower epicalyx bractlets. Potentilla subvahliana is tetraploid, perhaps an allopolyploid, and could consist of lineages from different parental combinations. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 9, p. 134. | FNA vol. 9, p. 203. |
Parent taxa | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Potentilla | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Niveae |
Sibling taxa | ||
Synonyms | P. canadensis var. pumila, P. canadensis var. villosissima, P. caroliniana, P. pumila | |
Name authority | Linnaeus: Sp. Pl. 1: 498. (1753) | Jurtzev: in A. I. Tolmatchew, Fl. Arct. URSS 9(1): 319. (1984) |
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