Potentilla bipinnatifida |
Potentilla jepsonii |
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bipinnate cinquefoil, potentille bipinnatifide, tansy cinquefoil |
Jepson's cinquefoil, Jepson's potentilla |
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Stems | ascending to erect, (1–)2–5 dm. |
decumbent to nearly erect, (0.2–)0.5–2.6 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. |
subpinnate to subpalmate, 1.5–10(–17) cm; petiole 0.5–4(–8) cm, long hairs ± abundant, spreading to loosely appressed, 0.5–2 mm, weak to stiff, short hairs absent or sparse, cottony or crisped hairs absent, glands sparse to abundant; leaflets (1–)2–3 per side, on distal 1/6–1/3(–1/2) of leaf axis, separate to slightly overlapping, terminal ones oblanceolate-elliptic to narrowly obovate, (0.5–)1–2.5(–3.5) × 0.4–1(–1.3) cm, margins strongly revolute, incised 3/4+ to midvein, undivided medial blade 1.5–3(–5) mm wide, teeth (2–)3–5(–6) per side, ± linear-elliptic to rarely ovate or oblanceolate, surfaces ± dissimilar, abaxial ± grayish, rarely white, long hairs ± abundant especially on veins, 1 mm, weak, short hairs absent or sparse, cottony hairs absent, crisped hairs sparse to abundant, glands ± abundant, sometimes obscured, adaxial green to gray-green, long hairs sparse to abundant, loosely appressed, 0.5–1(–2) mm, short hairs absent or sparse, cottony and crisped hairs absent, glands ± abundant. |
Cauline leaves | 2–4. |
1–2. |
Inflorescences | (4–)10–50(–100)-flowered, congested or elongating in fruit. |
(1–)3–12(–20)-flowered, congested, scarcely opening in fruit. |
Pedicels | 0.2–0.8 cm (proximal to 2 cm). |
0.2–0.5 cm (proximal to 1.2 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 elliptic to linear, 1.5–3 × (0.3–)0.5–1.2 mm, lengths 1/2–3/4 times sepals, margins flat; hypanthium 2.5–5 mm diam.; sepals 2–5 mm, apex usually ± acute to obtuse, rarely acuminate, abaxial surfaces: venation faint, glands abundant, evident; petals pale yellow, 2–5 × 2–4 mm, lengths ± equal to sepals; filaments 0.5–2 mm, anthers 0.3–0.7 mm; carpels 20–60, styles papillate-swollen in proximal 1/2–3/4+, 0.8–1.2 mm. |
Achenes | 1–1.2 mm, smooth to faintly rugose. |
1 mm, smooth to faintly rugose. |
2n | = 56. |
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Potentilla bipinnatifida |
Potentilla jepsonii |
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Phenology | Flowering summer. | Flowering summer. |
Habitat | Open shortgrass prairie, alkaline bottoms, streamsides in sagebrush, disturbed sites | Seasonally moist sites in alpine meadows, ridges, fellfields, rock ledges, talus slopes |
Elevation | 10–3400 m (0–11200 ft) | 2500–3700 m (8200–12100 ft) |
Distribution |
AK; CO; ID; MI; MN; MT; ND; NE; NM; SD; UT; WY; AB; MB; NT; ON; QC; SK; YT
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AZ; CA; CO; ID; MT; NV; OR; UT; WA; AB |
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.) |
Potentilla jepsonii (a replacement name for P. pensylvanica var. ovium) is widespread at higher elevations in the Intermountain Region, extending into the Sierra Nevada in California and the Rocky Mountains in Idaho and Wyoming. Disjunct occurrences are known on the north rim of the Grand Canyon and San Francisco Peaks, Arizona, and Steens Mountain, Oregon. Collections have most commonly been included in P. pensylvanica (for example, B. Ertter 1993; N. H. Holmgren 1997b); they differ in leaf division, vestiture, and epicalyx bractlets. J. Soják considered var. ovium to be a variety of P. litoralis, which has comparable leaves and vestiture; P. jepsonii lacks the enlarged, revolute epicalyx bractlets that distinguish P. litoralis and is for the most part well separated geographically and elevationally. The exception is the montane phase of P. litoralis, which, at the current stage of knowledge, is somewhat arbitrarily delimited from P. jepsonii in the northern Rocky Mountains; collections from Waterton Lakes National Park in Alberta and the Okanogan Mountains in Washington are tentatively placed here in P. jepsonii. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 9, p. 217. | FNA vol. 9, p. 216. |
Parent taxa | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Pensylvanicae | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Pensylvanicae |
Sibling taxa | ||
Synonyms | P. pensylvanica var. bipinnatifida | P. pensylvanica var. ovium, P. litoralis var. ovium |
Name authority | Douglas: in W. J. Hooker, Fl. Bor.-Amer. 1: 188. (1832) | Ertter: J. Bot. Res. Inst. Texas 2: 202. (2008) |
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