Potentilla sect. Aureae |
Potentilla robbinsiana |
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dwarf mountain cinquefoil, Robbins' cinquefoil, White Mountains cinquefoil |
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Habit | Perennials, tufted to cushion-forming or matted, rarely rosetted, not stoloniferous (except sometimes P. verna); taproots not fleshy-thickened; vestiture primarily of straight hairs, not differentiated into long and short, glands absent or sparse to abundant, sometimes red (P. hyparctica). | Plants tufted to densely matted; caudex branches short, ± slender, often embedded in old leaf bases. | ||||||||||||||||||||||||||||||||||||||||||||||||
Stems | usually ascending to erect, sometimes prostrate to decumbent or spreading, not flagelliform, not rooting at nodes (except P. verna), lateral to persistent basal rosettes, 0.1–2(–3) dm, lengths 1–3(–4) times basal leaves. |
spreading to erect, 0.1–0.4 dm, lengths 1–2 times basal leaves. |
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Leaves | basal sometimes 2-ranked; cauline 0–2(–3); primary leaves ternate or palmate, (0.5–)1–12(–20) cm; petiole: long hairs absent or spreading to ascending, weak to ± stiff, glands usually absent or sparse, sometimes abundant; leaflets 3–7, at tip of leaf axis, overlapping or not, broadly oblanceolate or obtriangular to flabellate, margins flat to revolute, distal 1/4–3/4+ evenly to unevenly incised 1/4–1/2 to midvein, sometimes 3–5-lobed 1/2–3/4 to midvein as well, primary teeth (1–)2–5(–7) per side or per lobe, surfaces ± similar, abaxial pale to dark green, rarely grayish, brownish, or reddish, cottony hairs absent, adaxial green to dark green, rarely brownish or reddish, sometimes ± glaucous (P. grayi), long hairs (if present) soft to weak, sometimes stiff. |
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Basal leaves | not in ranks, ternate, 1–2 cm; stipules: apex broadly acute; petiole 0.7–3 cm, long hairs sparse to abundant, spreading to subappresed, 0.2–2 mm, weak, glands sparse to common; leaflets 3, central obovate, 0.5–1.3 × 0.2–1 cm, petiolule 0–1 mm, margins flat to ± revolute, not lobed, distal ± 2/3 evenly incised ± 1/2 to midvein, teeth 2–4(–5) per side, surfaces similar, green, hairs ± abundant (or nearly absent adaxially), 0.5–1 mm, glands sparse to common. |
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Inflorescences | 1–6(–12)-flowered, ± cymose, ± to very open, or solitary flowers. |
1(–2)-flowered. |
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Pedicels | usually straight in fruit (often recurved in P. verna), (0–)0.2–3(–9) cm, proximal usually not much longer than distal (sometimes longer in fruit). |
straight, 0.5–3 cm, not much longer in fruit than in flower. |
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Flowers | 5-merous; hypanthium 2–7 mm diam.; petals pale to dark yellow, mostly ± obcordate (to orbiculate in P. elegans), (2–)3–10(–12) mm, usually longer than sepals, apex usually ± retuse; stamens ca. 20; styles subapical, columnar, filiform, or tapered, not, scarcely, or ± papillate-swollen in proximal 1/5–1/2, 0.8–2.5 mm. |
epicalyx bractlets oblong to elliptic, (1.8–)2–2.5(–3) × 0.7–1.2(–1.4) mm, ± equal to sepals, margins flat to ± revolute; hypanthium (4–)5–7 mm diam.; sepals (1.8–)2–2.5(–3) mm, apex broadly acute; petals yellow, 2–3 × 2–3 mm; filaments 0.5–1 mm, anthers 0.4–0.6 mm; carpels 20–30, styles columnar-tapered, sometimes ± papillate-swollen in proximal 1/3–1/2, 0.8–1 mm. |
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Achenes | ± smooth. |
1–1.3 mm. |
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2n | = 49. |
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Potentilla sect. Aureae |
Potentilla robbinsiana |
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Phenology | Flowering summer. | |||||||||||||||||||||||||||||||||||||||||||||||||
Habitat | Moist rocky slopes and flats, in montane tundra | |||||||||||||||||||||||||||||||||||||||||||||||||
Elevation | 1400–1600 m (4600–5200 ft) | |||||||||||||||||||||||||||||||||||||||||||||||||
Distribution | North America; Eurasia [Reportedly introduced in s Australia] |
NH; VT |
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Discussion | Species ca. 30 (10 in the flora). The circumscription of sect. Aureae used here largely follows that of B. C. Johnston (1985), except that Potentilla sierrae-blancae is placed in sect. Concinnae and P. rubella and P. stipularis are in sect. Chrysanthae. Other treatments (for example, P. A. Rydberg 1908d; T. Wolf 1908) split the species included here in two groups and/or recombine them with species in other sections, notably sect. Ranunculoides (Th. Wolf) Juzepczuk. Since Potentilla glaucophylla (sect. Graciles) and P. cottamii (sect. Subviscosae) are sometimes identified as members of sect. Aureae, they are included herein and key out in the third and twelfth couplets, respectively. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. Potentilla robbinsiana is known only from two sites in the White Mountains, Monroe County, New Hampshire, and is reported in Vermont. Additional populations have been established nearby as a result of transplant efforts. Listed in 1980 as a federally endangered species, an intense recovery program resulted in the species being delisted in 2002. Some early specimens were distributed as Potentilla frigida Villars, a similar European species. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 9, p. 188. | FNA vol. 9, p. 194. | ||||||||||||||||||||||||||||||||||||||||||||||||
Parent taxa | ||||||||||||||||||||||||||||||||||||||||||||||||||
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Synonyms | P. unranked Aureae, P. ser., P. section Frigidae | P. minima var. robbinsiana, P. hyparctica subsp. robbinsiana | ||||||||||||||||||||||||||||||||||||||||||||||||
Name authority | (Rydberg) Juzepczuk: in V. L. Komarov et al., Fl. URSS 10: 197. (1941) | (Lehmann) Oakes ex Rydberg: Bull. Torrey Bot. Club 23: 304. (1896) | ||||||||||||||||||||||||||||||||||||||||||||||||
Web links |