Potentilla sect. Aureae |
Potentilla hyparctica |
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arctic cinquefoil, subarctic 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 cushion-forming; caudex branches short to elongate, 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. |
ascending to erect, 0.2–2(–2.5) dm, lengths 1–3(–4) 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–)2–8(–10) cm; stipules: apex ± acute; petiole 1–6.5(–8.5) cm, long hairs sparse to common, spreading to subappressed, 0.8–2 mm, weak to ± stiff, glands sparse to common; leaflets 3, central obovate to broadly obovate, 0.5–2.5(–2.8) × 0.3–2(–2.2) cm, petiolule 0–3 mm, margins flat or slightly revolute, not lobed, distal 1/2–2/3(–3/4) evenly incised ± 1/2 to midvein, teeth (2–)3–5 per side, surfaces ± similar, abaxial usually pale green, sometimes grayish, hairs sparse to abundant, 0.5–1.7 mm, adaxial darker green, hairs and glands sparse. |
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Inflorescences | 1–6(–12)-flowered, ± cymose, ± to very open, or solitary flowers. |
1–3(–5)-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, 0.3–3 cm in flower, to 9 cm in fruit. |
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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 narrowly to broadly oblong or ovate, 3.5–7 × 1.5–5 mm, margins flat; hypanthium 4–7 mm diam.; sepals 4–8 mm, apex subacute to rounded; petals pale or bright yellow, 4–9 × 4–6 mm; filaments 0.5–1.1 mm, anthers 0.2–0.4 mm; carpels 50–80, styles ± columnar, not or scarcely papillate-swollen proximally, 0.6–0.9 mm. |
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Achenes | ± smooth. |
1.1–1.3 mm. |
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Potentilla sect. Aureae |
Potentilla hyparctica |
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Distribution | North America; Eurasia [Reportedly introduced in s Australia] |
AK; MT; WA; WY; AB; BC; NL; NT; NU; QC; YT; n Eurasia; circumpolar |
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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.) |
Subspecies 3 (2 in the flora). Southern arctic and subarctic plants differ from the northern arctic ones in presumably independent features. Where the two forms are sympatric (western Greenland, northern Quebec, Baffin Island), they appear to remain distinct even in mixed populations and are accordingly treated as subspecies. Although some features of scattered plants in Alaska and Yukon approach subsp. nivicola Jurtzev & V. V. Petrovsky (described from northeastern Asia), such plants do not otherwise correspond fully with this taxon. Possible hybrids between Potentilla hyparctica and P. pulchella (sect. Pensylvanicae) are addressed in the discussion of sect. Pensylvanicae. Presumed hybrids with P. villosa from the Aleutian Islands, characterized by the combination of basally thickened styles and lack of cottony hairs on leaflet abaxial surfaces, have been named P. ×aleutica Soják. (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. 192. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Parent taxa | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sibling taxa | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
Subordinate taxa | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
Synonyms | P. unranked Aureae, P. ser., P. section Frigidae | P. robbinsiana subsp. hyparctica | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Name authority | (Rydberg) Juzepczuk: in V. L. Komarov et al., Fl. URSS 10: 197. (1941) | Malte: Rhodora 36: 177. (1934) | ||||||||||||||||||||||||||||||||||||||||||||||||||||
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