Potentilla canadensis |
Potentilla johnstonii |
|
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dwarf cinquefoil |
sagebrush cinquefoil |
|
Stems | initially ascending to erect, soon becoming prostrate, flagelliform, not branched, eventually rooting at some nodes, (0.3–)0.5–12 dm. |
0.4–2 dm, lengths 2 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. |
palmate, 3–8(–13) cm; petiole 1.5–5(–8) cm, straight hairs abundant, ± appressed, 1–2 mm, stiff, cottony hairs absent, glands sparse to abundant; leaflets (3–)5–7(–9), on tip or at least less than distal 1/10 of leaf axis, separate to slightly overlapping, proximal pair separated from others by 0–1 mm of leaf axis, central leaflets narrowly cuneate to oblanceolate, 1–3(–4) × 0.3–0.7 cm, petiolule 1 mm, distal 1/4 or less of margins incised 1/3–2/3 to midvein, teeth 1(–3) per side, separate, 1–2(–4) mm, surfaces similar, green to grayish, straight hairs sparse to common, appressed, 1–1.5(–2) mm, stiff (sometimes softer and wavy), cottony hairs absent, glands sparse to abundant. |
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. |
4–11-flowered. |
Pedicels | (1–)2–5(–9) cm. |
0.7–2(–4) cm. |
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, 2–4 × 1 mm; hypanthium 3–4(–6) mm diam.; sepals 3–4.5 mm, apex acute to obtuse; petals 5–7 × 3–5 mm; filaments 1–2.5 mm, anthers 0.6–0.8 mm; carpels 3–10, styles 2–2.5 mm. |
Achenes | 1.2–1.4 mm, smooth. |
2.5 mm, smooth to slightly rugose. |
Rootstocks | erect, stout, 0.5–2 cm. |
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2n | = 28. |
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Potentilla canadensis |
Potentilla johnstonii |
|
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 | Rocky slopes in pinyon-juniper woodlands, with Artemisia |
Elevation | 0–1500 m (0–4900 ft) | 2300–2500 m (7500–8200 ft) |
Distribution |
CT; DC; DE; KY; MA; MD; ME; MO; NC; NH; NJ; NY; OH; PA; RI; SC; TN; VA; VT; WV; NS; ON
|
NV |
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.) |
Of conservation concern. Potentilla johnstonii occurs only in the Quinn Canyon Range in Nye County. Its distinctiveness was first noted by B. C. Johnston (1980), who treated it as a variety of P. concinna using the unpublished epithet curvata. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 9, p. 134. | FNA vol. 9, p. 182. |
Parent taxa | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Potentilla | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Concinnae |
Sibling taxa | ||
Synonyms | P. canadensis var. pumila, P. canadensis var. villosissima, P. caroliniana, P. pumila | |
Name authority | Linnaeus: Sp. Pl. 1: 498. (1753) | Soják: Thaiszia 16: 97. (2007) |
Web links |