Potentilla newberryi |
Potentilla lasiodonta |
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Newberry's cinquefoil |
Sandhills cinquefoil |
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Stems | ± erect, 2–4 dm. |
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Basal leaves | petiole 1–3.5 cm, long hairs ± abundant, 0.5–1.5 mm, short hairs absent or sparse, rarely common; leaflets 0.2–1 cm, lobes oblanceolate to narrowly elliptic, (0.5–)1–2 mm wide, longs hairs ± abundant, short hairs absent or sparse, glands sparse to abundant. |
pinnate, 12–20(–30) cm; petiole 5–10(–15) cm, long hairs ± abundant, spreading to ascending, 0.5–1 mm, weak to ± stiff, short hairs abundant to dense, cottony or crisped hairs absent, glands sparse to abundant, often obscured; leaflets 4–6(–9) per side, on distal (1/3–)1/2–3/5 of leaf axis, slightly overlapping, terminal ones oblanceolate to narrowly elliptic, 3–6 × 0.8–1.2(–1.5) cm, margins strongly revolute, incised ± 1/2 to midvein, undivided medial blade 5–9 mm wide, teeth 8–12 per side, narrowly triangular to lanceolate, surfaces ± dissimilar, abaxial grayish, long hairs ± sparse (or not differentiated from short hairs), 0.5–1.5 mm, weak, short hairs abundant to dense, cottony or crisped hairs absent, glands sparse or obscured, adaxial ± green, straight hairs (long and short not differentiated) abundant, spreading to ascending, 0.2–0.5 mm, cottony and crisped hairs absent, glands sparse to abundant, often obscured. |
Cauline leaves | (1–)2–4. |
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Inflorescences | 10–40-flowered, congested or elongating in fruit. |
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Pedicels | ± 0.1 cm (proximal to 1.2 cm). |
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Flowers | epicalyx bractlets broadly lanceolate to elliptic, 1.5–4(–5) × (0.4–)0.8–1.3 mm; sepals 2–4(–5) mm, apex ± acute; petals (3–)4–6 × (2–)3–5 mm; filaments 1–2(–2.5) mm, anthers 0.4–0.6 mm; carpels 20–50. |
epicalyx bractlets narrowly ovate-acuminate, (3–)4–8(–10) × 2–3 mm, lengths 1–2 times sepals, margins ± revolute; hypanthium (4–)5–10 mm diam.; sepals 3–5 mm, apex acute to obtuse, abaxial surfaces: venation moderate, glands ± abundant, obscured to evident; petals pale yellow, 3–5 × 2–4 mm, lengths ± equal to or shorter than sepals; filaments 1–1.5 mm, anthers 0.5–0.8 mm; carpels 80–90, styles papillate-swollen in proximal 3/4+, 1–1.2 mm. |
Achenes | 0.9–1.2 mm. |
± 1 mm, ± rugose. |
2n | = 14. |
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Potentilla newberryi |
Potentilla lasiodonta |
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Phenology | Flowering summer. | Flowering summer. |
Habitat | Moist, sandy to clayey, more or less alkaline soil, especially where seasonally inundated near streams, ponds, and lakes | Sandy sites in prairies |
Elevation | 1300–1800 m (4300–5900 ft) | 300–1100 m (1000–3600 ft) |
Distribution |
CA; NV; OR; WA
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MN; ND; AB; MB; SK |
Discussion | Potentilla newberryi grows in valley bottoms in south-central Oregon, northeastern California, and northwestern Nevada. The only specimen supposedly collected in south-central Washington (W. N. Suksdorf 2718, WTU) was gathered in 1898. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Potentilla lasiodonta is a diploid relative of tetraploid P. pensylvanica, sharing similar velvety vestiture of dense short hairs, pinnate leaves, and epicalyx bractlets with revolute margins. The species differs in having larger epicalyx bractlets and less deeply incised leaflets. Plant height and leaf size are at the upper range of P. pensylvanica, and populations are evidently restricted to sandy substrates. Occurrence in Manitoba is based on B. L. Kohli and J. G. Packer (1976); no vouchers are in WIN. At least one collection from southeastern British Columbia (Brown 779, MO) approaches P. lasiodonta, but it is insufficient by itself to serve as a provincial record. The fundamental ploidy and epicalyx distinctions of this species were established by B. L. Kohli and J. G. Packer (1976), who proposed the name Potentilla finitima. As noted by J. Soják (1994), the type of P. lasiodonta is the same entity. Potentilla atrovirens Rydberg and P. pensylvanica var. arida B. Boivin have sometimes been applied to this taxon; the types of both names fall within the circumscription of P. pensylvanica in the narrow sense (Packer, pers. comm.). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 9, p. 137. | FNA vol. 9, p. 214. |
Parent taxa | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Arenicolae | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Pensylvanicae |
Sibling taxa | ||
Synonyms | Ivesia gracilis | P. finitima |
Name authority | A. Gray: Proc. Amer. Acad. Arts 6: 532. (1865) — not P. gracilis Douglas ex Hooker 1830 | Rydberg: in N. L. Britton et al., N. Amer. Fl. 22: 351. (1908) |
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