Potentilla rivalis
Potentilla sanguinea
brook cinquefoil, brook or river cinquefoil, river cinquefoil, streambank cinquefoil
Flagstaff cinquefoil
decumbent to erect, sometimes prostrate, (0.5–)1–4(–7) dm, hairs at base not stiff, not tubercle-based, glands absent or sparse, inconspicuous.
3–7(–10) dm.
ternate, palmate, or subpalmate (with distal leaflets ± confluent), basal 3–15(–25) cm, cauline 2–7(–12) cm;
petiole: basal 1–9(–16) cm, cauline 0.5–4(–8) cm, long hairs usually common to abundant, ascending to spreading, 0.5–1.5 mm, usually ± weak, ± crisped hairs common to abundant, glands absent or sparse, inconspicuous;
leaflets 3–5(–7), at tip to distal 1/5 (basal) or 1/2 (cauline) of leaf axis, separate to ± overlapping, largest ones oblanceolate-elliptic to obovate, (0.5–)1–5(–6) × 0.5–2(–2.5) cm, distal 1/2–3/4 of margin evenly to unevenly incised 1/3–1/2 to midvein, sometimes cleft nearly to base, teeth 3–8 per side, surfaces moderately to abundantly hairy, glands absent or sparse.
± subpalmate, sometimes palmate, (4–)6–15(–21) cm;
petiole (2–)4–10(–15) cm, long hairs sparse to abundant, spreading to weakly appressed, 0.5–2(–3) mm, weak to ± stiff, glands sparse to abundant;
leaflets (5–)7, on less than distal 1/10 (1–5[–10] mm) of leaf axis, central one 1–6(–7) × 1–2(–3) cm, petiolules 0(–6) mm, distal 1/2–3/4 (sometimes nearly whole), margin incised 1/5 or less to midvein, teeth 4–10(–15) per side, 1–2(–3) mm, teeth apex ± obtuse, surfaces ± similar, abaxial green, straight hairs sparse to abundant, especially on veins, 0.5–1.5 mm, cottony hairs absent, glands ± sparse or absent, adaxial slightly paler green, hairs shorter and sparser.
stipules usually entire.
(5–)20–100+-flowered.
(4–)8–40(–70)-flowered.
0.2–1(–2) cm.
0.3–2 cm.
epicalyx bractlets narrowly elliptic to ovate, (1.5–)2–4(–6) × 0.8–1.5 mm;
hypanthium (2–)3–5 mm diam.;
sepals 3–5 mm, apex broadly acute to obtuse;
petals pale yellow to yellow, broadly oblong-obovate, 1.5–2 × 1 mm;
stamens (5–)10(–15), filaments 0.4–0.9 mm, anthers 0.2–0.3 mm;
carpels 40–100, styles 0.5–0.6 mm.
epicalyx bractlets lanceolate-elliptic, 3.5–8 × 1–1.5(–2) mm;
sepals 4–8(–10) mm, apex acuminate;
petals dark reddish proximally, reddish orange distally, (3.5–)5–9 × 5–10 mm;
filaments 1.5–2.5 mm, anthers 0.8 mm;
carpels 30–40, styles 2–3 mm.
yellowish, 0.7–0.9 mm, ± smooth, without a corky protuberance.
1.5–2 mm, lightly rugose.
= 14, 70.
Potentilla rivalis
Potentilla sanguinea
Potentilla rivalis is most abundant in central and western North America; reports of occurrences in more eastern states (including those listed here) need confirming, as P. rivalis and P. norvegica often have been confused. Potentilla leucocarpa Rydberg was provided as a superfluous replacement name for P. millegrana; specimens annotated by Rydberg with this name include both P. biennis and P. rivalis.
Potentilla rivalis is sometimes divided into three species or varieties (for example, H. J. Scoggan 1978–1979). In a strict sense, var. rivalis has subpalmately compound (5-foliate) leaves. Variety milligrana, the most common phase, has 3-foliate leaves. Plants with both 3- and 5-foliolate leaves are var. pentandra, which also tends to have five stamens, though this latter character is not correlated with the leaf features. On the Great Plains, where var. pentandra is confined, all three expressions are often found in a single population (R. L. McGregor 1986b).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Of conservation concern.
Potentilla sanguinea is known only from south and east of Flagstaff, Coconino County. The species may be a hybrid between P. thurberi var. thurberi and P. hippiana or another member of sect. Leucophyllae that occurs sympatrically.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
- Local floras:
BC, 
CA, 
OR, 
WA - Local Web sites: CalFlora, CalPhotos,
Flora NW, 
Go Botany, 
IL Wildflowers, 
KS Wildflowers, 
MD Biodiversity, 
MN Wildflowers, 
MO Plants, 
PNW Herbaria, Turner Photog. 
WildflowerSearch
iNaturalist (observations)
USDA Plants Database- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
