Potentilla breweri |
Potentilla gracilis |
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Brewer's cinquefoil |
graceful cinquefoil, northwest cinquefoil, potentille grêle, slender cinquefoil |
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Habit | Plants rosetted to ± matted; taproots not fleshy-thickened. | |||||||||||||||||
Glands | usually absent or inconspicuous, uncolored. |
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Stems | prostrate to ascending, (0.5–)1–3(–4.5) dm, lengths 2–4(–5) times basal leaves. |
ascending to erect, (0.5–)2–7(–12) dm. |
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Basal leaves | pinnate with distal leaflets ± confluent, (2–)4–12(–17) × 1–2.5(–5) cm; petiole 1–3(–7) cm, straight hairs mostly absent, cottony hairs sparse to dense, glands absent or obscured to common; primary lateral leaflets 3–6 per side, on distal 1/2–2/3(–3/4) of leaf axis, ± overlapping, largest ones cuneate-flabellate, 0.5–1.5(–2.5) × 0.4–2(–3) cm, distal 1/2 to whole margin unevenly incised 1/2 to completely to midvein (blade often medially split as well), ultimate teeth or segments 3–10, narrowly elliptic, 2–10(–15) × 1–3(–5) mm, apical tufts less than 1 mm, surfaces grayish green to white, not glaucous, straight hairs sparse to common (sparser adaxially), loosely appressed to ascending, 1–1.5 mm, soft, cottony hairs sparse to dense, glands sparse or obscured to common. |
usually not in ranks, palmate, rarely subpalmate, 4–40(–55) cm; petiole (2–)3–25(–45) cm, long hairs sparse to dense, appressed to spreading, 0.5–2(–3) mm, weak to stiff, short hairs absent, crisped hairs usually absent, cottony hairs absent or sparse to abundant (var. owyheensis), glands absent or sparse; leaflets 5–9, on tip, rarely less than distal 1/10, of leaf axis, separate to overlapping, largest ones oblanceolate to elliptic or obovate, (1.5–)2–9(–11) × (0.7–)1.5–4 cm, margins flat to revolute, distal (2/3–)3/4 to nearly whole length evenly to unevenly incised 1/4–3/4+ to midvein, undivided medial blade 2–20 mm wide, teeth (4–)6–10(–11) per side (sometimes secondarily toothed), linear to broadly lanceolate, 2–20(–35) mm, surfaces ± similar to strongly dissimilar, abaxial green or pale green to white, usually not glaucous, long hairs sparse to abundant (sometimes mostly on veins), short-crisped hairs absent or sparse to abundant, cottony hairs absent or sparse to dense, glands usually absent or obscured to sparse, sometimes common, adaxial dark green to grayish, long hairs sparse to ± abundant, rarely absent or dense, short-crisped hairs absent or sparse, cottony hairs absent or sparse to abundant (var. owyheensis), glands usually absent or sparse to sometimes common. |
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Cauline leaves | 1–3. |
1–4(–5). |
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Inflorescences | 2–15(–25)-flowered, openly cymose. |
(4–)10–50(–60)-flowered. |
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Pedicels | (1–)1.5–2.5(–4) cm, straight in fruit. |
0.3–3 cm. |
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Flowers | epicalyx bractlets lanceolate to ovate, 2–5 × 1–1.5 mm; hypanthium (3–)4–5 mm diam.; sepals (3–)4–7 mm, apex acute; petals 5–9(–10) × 4–8(–10) mm; filaments (1–)2–4 mm, anthers (0.5–)1 mm; carpels 15–25, styles 2–3 mm. |
epicalyx bractlets linear to narrowly lanceolate or elliptic, 2–6(–8) × 0.5–1.5(–2.5) mm, hairs sparse to abundant, rarely dense, ± appressed to ascending, rarely spreading, glands usually absent or inconspicuous; hypanthium 3.5–6 mm diam.; sepals 4–8(–10) mm, apex acute to long acuminate; petals (3–)4–10(–11) × (3–)4–10(–12) mm; filaments (1–)1.5–2.5(–3.5) mm, anthers 0.6–1.2(–1.6) mm; carpels (15–)20–50, styles ± tapered, papillate-swollen proximally, (1–)1.5–2.5(–3) mm. |
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Achenes | 1.8 mm, smooth, not carunculate. |
1–1.8 mm. |
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2n | = 72–73, 99, 100, 102. |
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Potentilla breweri |
Potentilla gracilis |
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Phenology | Flowering summer. | |||||||||||||||||
Habitat | Rocky meadows, seasonally moist flats, rock crevices, often near streams and lakes | |||||||||||||||||
Elevation | 1500–3600 m (4900–11800 ft) | |||||||||||||||||
Distribution |
CA; NV; OR; WA
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AK; AZ; CA; CO; ID; MI; MN; MT; ND; NV; OR; SD; UT; WA; WI; WY; AB; BC; MB; NT; ON; PE; QC; SK; YT
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Discussion | Of conservation concern. Potentilla breweri differs from other members of sect. Multijugae in its often dense, cottony vestiture. Density of cottony hairs and leaflet dissection can differ significantly between first-formed and mid- to late-season leaves of P. breweri; in the description above, leaves are those predominant at anthesis. Potentilla breweri is most common in the Sierra Nevada of California, with sporadic occurrences to the Cascade Range in southern Washington. Disjunct populations occur in the Ruby and Snake ranges in Nevada and on Steens Mountain in Oregon, where often introgressed with P. versicolor. Reports from Utah are based on collections of P. concinna var. proxima or possible hybrids between P. concinna var. proxima and P. ovina var. decurrens. J. Clausen et al. (1940) concluded that Potentilla breweri (with P. versicolor as synonym) belonged with P. bruceae and P. drummondii as members of a cenospecies that probably also included unnamed species (possibly P. ovina var. decurrens) from the mountains of Colorado, Utah, and Wyoming. Chromosome number varied within populations, and high numbers of univalents were present. Recognition of Potentilla breweri as a distinct species differs from recent treatments in which it was considered to be a variety or subspecies of P. drummondii, parallel to the treatment of P. bruceae. The present continental perspective of the genus, as well as additional fieldwork, has resulted in the return of all three to species rank (B. Ertter and D. Mansfield 2007). Placement of P. breweri in sect. Multijugae, separate from P. bruceae and P. drummondii in sect. Graciles, is based on the commonly prostrate habit, fully pinnate leaves, and deeply divided overlapping leaflets. Although B. C. Johnston (1980) used Potentilla breweri var. viridis Jepson to accommodate greener-than-average sparsely cottony plants, including populations treated here as P. versicolor, the type is probably a sterile hybrid with P. wheeleri as one parent (B. Ertter 1992). The type of P. millefolia var. algida Jepson (included by Johnston in the synonymy of var. viridis) and comparable plants from north-central California combine features of P. breweri and P. versicolor but are more glandular than either. This variant, as well as exceptionally small plants from the Warner Mountains of California, may prove distinct. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Varieties 5 (5 in the flora). Because variation within Potentilla gracilis and other members of sect. Graciles is still far from resolved, taxonomic recognition is given to only the most distinctive extremes and that mostly at the varietal level. The goal is to call attention to areas that need study rather than to provide a full resolution, and even this leaves out some large, widespread populations in both keys and descriptions. The taxonomic placement of some available names, such as P. glomerata A. Nelson, P. longipedunculata Rydberg, and P. macropetala Rydberg, likewise remains unresolved. The vouchers for the report by M. L. Fernald (1950) of Potentilla gracilis and P. pulcherrima from New Hampshire are presumably specimens collected in Coos County by A. S. Pease (NEBC). The three collections differ from one another, corresponding most closely to var. fastigiata, var. flabelliformis, and P. pulcherrima. The presence of such diversity in the same meadow, all as disjunct occurrences, suggests an artificial, non-persisting introduction. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 9, p. 170. | FNA vol. 9, p. 153. | ||||||||||||||||
Parent taxa | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Multijugae | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Graciles | ||||||||||||||||
Sibling taxa | ||||||||||||||||||
Subordinate taxa | ||||||||||||||||||
Synonyms | P. drummondii subsp. breweri, P. drummondii var. breweri, P. plattensis var. leucophylla | |||||||||||||||||
Name authority | S. Watson: Proc. Amer. Acad. Arts 8: 555. (1873) | Douglas ex Hooker: Bot. Mag. 57: plate 2984. (1830) | ||||||||||||||||
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