Potentilla rivalis
Potentilla townsendii
brook cinquefoil, brook or river cinquefoil, river cinquefoil, streambank cinquefoil
Townsend's cinquefoil
absent or inconspicuous, uncolored.
decumbent to erect, sometimes prostrate, (0.5–)1–4(–7) dm, hairs at base not stiff, not tubercle-based, glands absent or sparse, inconspicuous.
ascending to nearly erect, (1–)2–5(–7.5) 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.
usually not in ranks, palmate, rarely subpalmate, (2–)5–20(–30) cm;
petiole (1–)2–15(–25) cm, long hairs usually absent or sparse and appressed, sometimes common and spreading, 1–1.5 mm, stiff, short, crisped, and cottony hairs absent, glands absent;
leaflets 5–7(–8), usually on tip, rarely on less than distal 1/10, of leaf axis, separate, largest ones narrowly oblanceolate-elliptic, (1.5–)2–5(–6) × 0.5–1.2(–1.5) cm, margins flat, distal (1/4–)1/2–3/4 evenly incised 1/4–1/3 to midvein, undivided medial blade 4–11 mm wide, teeth (2–)4–8(–9) per side, mostly broadly lanceolate, 1–2 mm, surfaces similar, green, not glaucous, long hairs usually absent or limited to veins and margins, short, crisped, and cottony hairs absent, glands absent.
1–3.
(5–)20–100+-flowered.
(5–)10–20(–25)-flowered.
0.2–1(–2) cm.
0.7–3(–3.5) 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 to elliptic, (2–)2.5–5(–6) × 0.5–1(–1.4) mm, hairs sparse, ± appressed, glands absent;
hypanthium 3.5–5 mm diam.;
sepals 4–8(–9) mm, apex acute to long acuminate;
petals 5–10 × 5–10(–12) mm;
filaments 1–3 mm, anthers (0.5–)0.6–1 mm;
carpels 15–30, styles filiform above papillate-swollen base, (1–)1.5–2 mm.
yellowish, 0.7–0.9 mm, ± smooth, without a corky protuberance.
1.1–1.6 mm.
= 14, 70.
Potentilla rivalis
Potentilla townsendii
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.)
Although previously applied only to collections from Chihuahua, Mexico, Potentilla townsendii is here used to accommodate most plants from Arizona and New Mexico previously placed in P. glaucophylla (as P. diversifolia Lehmann). Plants have narrow, shallowly toothed leaflets; stems, petioles, and leaflet veins that are often reddish; and larger anthers than P. glaucophylla. As now circumscribed, P. townsendii is known in the United States primarily from the White Mountains of east-central Arizona and the high mountains of northern New Mexico. Whether these plants are truly conspecific with those from Chihuahua, Mexico, remains to be confirmed. The species might also occur in Colorado and Utah, but the best disposition of these problematic populations is uncertain. Somewhat hairy plants with subpalmate leaves are interpreted as introgression from P. hippiana or other species.
(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
