Potentilla bipinnatifida |
Potentilla biflora |
|
---|---|---|
bipinnate cinquefoil, potentille bipinnatifide, tansy cinquefoil |
two-flower cinquefoil |
|
Stems | ascending to erect, (1–)2–5 dm. |
|
Basal leaves | subpinnate to subpalmate, (6–)10–25 cm; petiole (2–)5–15 cm, long hairs dense, appressed, 1–2 mm, soft to ± stiff, short hairs absent, crisped hairs sparse, glands absent, sparse, or obscured; leaflets 2–3 per side, on distal 1/6–1/3(–1/2) of leaf axis, separate to ± overlapping, terminal ones oblanceolate, (2–)3–6(–10) × 1–2(–3.5) cm, margins revolute, incised 3/4+ to midvein, undivided medial blade 1.5–6 mm wide, teeth 5–8 per side, ± linear, surfaces ± to strongly dissimilar, abaxial usually white, rarely grayish, long hairs abundant especially on veins, 1–2 mm, ± weak, short hairs absent or obscured, cottony (and crisped) hairs ± dense, glands absent or obscured, adaxial green to grayish, long hairs sparse to abundant, loosely appressed, 0.5–1.5 mm, short hairs absent or sparse, crisped and/or cottony hairs sparse to common, glands sparse to common. |
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 | 2–4. |
|
Inflorescences | (4–)10–50(–100)-flowered, congested or elongating in fruit. |
|
Pedicels | 0.2–0.8 cm (proximal to 2 cm). |
|
Flowers | epicalyx bractlets narrowly elliptic to lanceolate, 2.5–6 mm, lengths ± 2/3 times sepals, margins flat; hypanthium 3–5 mm diam.; sepals 3–6 mm, apex ± acute, abaxial surfaces: venation indistinct, glands absent, sparse, or obscured; petals yellow, 3–5 × 3–4 mm, lengths ± equal to sepals; filaments 0.5–2 mm, anthers 0.3–0.5 mm; carpels 50–80, styles papillate-swollen in proximal 1/2–3/4+, 1–1.2 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 | 1–1.2 mm, smooth to faintly rugose. |
1.5–2 mm. |
2n | = 56. |
= 14. |
Potentilla bipinnatifida |
Potentilla biflora |
|
Phenology | Flowering summer. | Flowering summer. |
Habitat | Open shortgrass prairie, alkaline bottoms, streamsides in sagebrush, disturbed sites | Dryas fellfields, gravel terraces, well-drained soil, often with seasonal seepage, on calcareous substrates |
Elevation | 10–3400 m (0–11200 ft) | 0–2000 m (0–6600 ft) |
Distribution |
AK; CO; ID; MI; MN; MT; ND; NE; NM; SD; UT; WY; AB; MB; NT; ON; QC; SK; YT
|
AK; BC; NT; NU; YT; Asia |
Discussion | Potentilla bipinnatifida is similar to P. litoralis in habit and leaf dissection but has flat, silky epicalyx bractlets and sepals with no evident glands. Vestiture is generally silkier, and the silvery to bicolor leaves are white-cottony abaxially. The two species are sympatric in the plains of Canada, with some intergradation; P. bipinnatifida is also common south to Colorado, where it is found in intermontane meadows and sagebrush flats. Outlying populations occur in Blaine and Custer counties, Idaho, and Duchesne and Piute counties, Utah. Eastern collections from disturbed sites might be adventive. Potentilla missourica Hornemann ex Lindley and P. normalis Besser ex Sprengel are older names for this species; both were rejected against a conserved P. bipinnatifida with designated lectotypes (see J. Soják 2008b). (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. 217. | FNA vol. 9, p. 131. |
Parent taxa | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Pensylvanicae | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Biflorae |
Sibling taxa | ||
Synonyms | P. pensylvanica var. bipinnatifida | |
Name authority | Douglas: in W. J. Hooker, Fl. Bor.-Amer. 1: 188. (1832) | D. F. K. Schlechtendal: Ges. Naturf. Freunde Berlin Mag. Neuesten Entdeck. Gesammten Naturk. 7: 297. (1816) |
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