Potentilla sect. Aureae
Rosaceae subfam. rosoideae
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.
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.
alternate, rarely opposite, pinnately compound, sometimes simple or palmately compound;
stipules present, rarely absent.
1–6(–12)-flowered, ± cymose, ± to very open, or solitary flowers.
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).
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.
torus usually enlarged, sometimes small or absent;
carpels 1–260(–450), distinct, free, styles distinct, rarely connate (Roseae);
ovules 1(or 2), collateral (Rubeae) or superposed (Fallugia, Filipendula).
achenes or aggregated achenes sometimes with fleshy, urn-shaped hypanthium or enlarged torus, sometimes aggregated drupelets;
styles persistent or deciduous, not elongate (elongate but not plumose in Geum).
± smooth.
= 7(8).
Potentilla sect. Aureae
Rosaceae subfam. rosoideae
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.)
Variation in the number of genera in subfam. Rosoideae is due to differences in generic delimitation between D. Potter et al. (2007) and the authors of some Potentilleae genera. Cyanogenic glycosides and sorbitol are absent in the subfamily.
Tribes 6, genera 28–35, species ca. 1600 (6 tribes, 26 genera, 302 species, including 1 hybrid, in the flora)
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Basal leaflets (3–)4–7 | → 2 |
1. Basal leaflets 3 | → 4 |
2. Basal leaves not in ranks; stems usually prostrate to decumbent, rarely weakly erect; caudex branches elongate and slender; pedicels often recurved; introduced. | P. verna |
2. Basal leaves 2-ranked; stems ascending to erect; caudex branches usually short and stout, sometimes elongate and slender; pedicels straight; native | → 3 |
3. Leaves glaucous, ± blue-green; styles 1.5–2.5(–3) mm; sepals: apex acute to short acuminate; w North America, Greenland. | P. glaucophylla (sect. Graciles) |
3. Leaves not glaucous, green; styles 1–1.6 mm; sepals: apex broadly acute; ne Canada, Greenland. | P. crantzii |
4. Central leaflets deeply 3–5-lobed (sinuses extending 1/2 to nearly to midvein), lobes unevenly incised 1/4–1/2 to midvein, teeth (1–)2–5 per lobe, glands sparse to abundant | → 5 |
4. Central leaflets not or shallowly lobed (sinuses extending less than 1/2 to midvein), evenly or unevenly incised 1/4–1/2 to midvein, teeth 2–7 per side, glands absent or sparse to common | → 6 |
5. Styles 1.3–2 mm; stems 0.3–2 dm; sepals 3–5 mm; nw California. | P. cristae |
5. Styles 0.7–0.9 mm; stems 0.1–0.5 dm; sepals 2.2–2.5 mm; arctic. | P. elegans |
6. Leaflet and epicalyx bractlet margins revolute; British Columbia, Alaska | → 7 |
6. Leaflet and epicalyx bractlet margins flat, sometimes slightly or ± revolute; North America | → 8 |
7. Petals 9–12 mm; caudex branches stout (diam. 1–2 cm, including old leaf-bases); filaments (2–)2.8–3.2 mm; styles 1.7–2 mm; 0–10 m. | P. fragiformis |
7. Petals 4–8 mm; caudex branches slender to ± stout (diam. 0.5–1 cm, including old leaf-bases); filaments 1.2–2 mm; styles 0.8–1.2 mm; 100–1100 m. | P. nana |
8. Styles 1–2.5 mm; filaments 1–3 mm | → 9 |
8. Styles 0.6–1 mm; filaments 0.5–1(–1.5) mm | → 11 |
9. Leaflet margins usually unevenly incised, teeth 3–7 per side, often secondarily toothed. | P. flabellifolia |
9. Leaflet margins evenly incised, teeth (2–)3–4(–5) per side, not secondarily toothed | → 10 |
10. Petioles: long hairs 1–2.5 mm; central leaflets: petiolules 0–1 mm; Greenland, ne Canada. | P. crantzii |
10. Petioles: long hairs 0.5–1 mm; central leaflets: petiolules (1–)3–10 mm; California. | P. grayi |
11. Epicalyx bractlets 3.5–7 mm; petals 4–9 mm. | P. hyparctica |
11. Epicalyx bractlets (1.8–)2–2.5(–3) mm; petals 2–3 mm | → 12 |
12. Epicalyx bractlets 1/2–3/4 as long as sepals; inflorescences 1–4-flowered; Great Basin. | P. cottamii (sect. Subviscosae) |
12. Epicalyx bractlets ± equal to sepals; inflorescences 1(–2)-flowered; New England. | P. robbinsiana |
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