Potentilla sect. Aureae

(Rydberg) Juzepczuk in V. L. Komarov et al.

in V. L. Komarov et al., Fl. URSS 10: 197. 1941.

Basionym: Aureae Rydberg Bull. Torrey Bot. Club 23: 394. 1896
Synonyms: Potentilla ser. Aureae (Rydberg) T. T. Yü & C. L. Li Potentilla sect. Frigidae (Rydberg) O. Stevens
Treatment appears in FNA Volume 9. Treatment on page 188. Mentioned on page 125, 144, 147, 152, 182, 187, 189, 195, 196, 201, 212, 218.

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). 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. 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. Inflorescences 1–6 (–12) -flowered, ± cymose, ± to very open, or solitary flowers. 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). 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. Achenes ± smooth.

Distribution

North America, Eurasia, reportedly in s Australia

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.

Selected References

None.

Key

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. Potentilla 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. Potentilla glaucophylla (sect. Graciles)
3 Leaves not glaucous, green; styles 1–1.6 mm; sepals: apex broadly acute; ne Canada, Greenland. Potentilla 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. Potentilla cristae
5 Styles 0.7–0.9 mm; stems 0.1–0.5 dm; sepals 2.2–2.5 mm; arctic. Potentilla 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. Potentilla 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. Potentilla 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. Potentilla 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. Potentilla crantzii
10 Petioles: long hairs 0.5–1 mm; central leaflets: petiolules (1–)3–10 mm; California. Potentilla grayi
11 Epicalyx bractlets 3.5–7 mm; petals 4–9 mm. Potentilla 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. Potentilla cottamii (sect. Subviscosae)
12 Epicalyx bractlets ± equal to sepals; inflorescences 1(–2)-flowered; New England. Potentilla robbinsiana

"dm" is not declared as a valid unit of measurement for this property.

... more about "Potentilla sect. Aureae"
pale +  and dark green rarely grayish brownish or reddish +
green +  and dark green rarely brownish or reddish +
Reidar Elven +, Barbara Ertter +, David F. Murray +  and James L. Reveal +
(Rydberg) Juzepczuk in V. L. Komarov et al. +
compound +  and simple +
Aureae +
25 cm250 mm <br />0.25 m <br /> (30 cm300 mm <br />0.3 m <br />) +
less cordate or reniform +  and narrowly elliptic +
0.5 cm5 mm <br />0.005 m <br /> (25 cm250 mm <br />0.25 m <br />) +
reduced +
free +  and distinct +
hairy +  and glabrous +
North America +, Eurasia +  and reportedly in s Australia +
not +  and aggregated +
5-merous +, solitary +  and open +
0.8 cm8 mm <br />0.008 m <br /> (2 cm20 mm <br />0.02 m <br />) +
unisexual +  and bisexual +
not +  and aggregated +
deciduous +
on style scar +, hairy +  and glabrous +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.26 cm2.6 mm <br />0.0026 m <br />) +
stoloniferous +  and short-rhizomatous +
straight +
stiff +, weak +  and more or less stiff +
spreading to ascending +
crisped +
not differentiated +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
0.7 cm7 mm <br />0.007 m <br /> (1 cm10 mm <br />0.01 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
cymose +  and 1-6(-12)-flowered +
crassinucellate +
bipinnate +, odd-pinnate +, subpalmate +, palmate +  and ternate +
opposite +  and alternate +
marcescent +
well-developed +
persistent +
cauline +  and basal +
reduced +
not +  and overlapping +
obtriangular +  and flabellate +
linear +  and oblanceolate +
palmate +  and pinnate +
1/2 +  and 3/4 +
3-5-lobed +, incised +, flat +  and revolute +
inferior +  and superior +
clustered +, biseriate +  and superposed +
3 cm30 mm <br />0.03 m <br /> (9 cm90 mm <br />0.09 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (3 cm30 mm <br />0.03 m <br />) +
1 cm10 mm <br />0.01 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
free +  and distinct +
usually longer +
0.3 cm3 mm <br />0.003 m <br /> (1 cm10 mm <br />0.01 m <br />) +
adnate +, free +, connate +  and distinct +
palmate +  and ternate +
12 cm120 mm <br />0.12 m <br /> (20 cm200 mm <br />0.2 m <br />) +
1 cm10 mm <br />0.01 m <br /> (12 cm120 mm <br />0.12 m <br />) +
usually not much longer +
in V. L. Komarov et al., Fl. URSS +
not arillate +
persistent +
free +  and distinct +
erect +  and spreading +
lanceolate +  and broadly ovate or deltate +
free +  and distinct +
not rooting +
reddish +  and green +
1-3(-4) times basal leaves +
spreading +, decumbent +, usually ascending +  and erect +
1 +  and many +
not flagelliform +
palmate +  and pinnate +
deciduous +
distinct +
subapical +
papillate-swollen +, tapered +, filiform +  and columnar +
rough-thickened +
Potentilla ser. +  and Potentilla sect. Frigidae +
not fleshy-thickened +
Potentilla sect. Aureae +
Potentilla +
section +
inconspicuous +
enlarged +
matted +  and cushion-forming +
biennial +, annual +  and perennial +
herb +  and matted +