Potentilla newberryi
Potentilla plattensis
Newberry's cinquefoil
Platte cinquefoil, Platte River cinquefoil
initially decumbent to sometimes ascending, becoming prostrate or supported by vegetation, (0.3–)0.5–3.5(–4.5) dm, lengths 1.5–2.5(–4) times basal leaves.
petiole 1–3.5 cm, long hairs ± abundant, 0.5–1.5 mm, short hairs absent or sparse, rarely common;
leaflets 0.2–1 cm, lobes oblanceolate to narrowly elliptic, (0.5–)1–2 mm wide, longs hairs ± abundant, short hairs absent or sparse, glands sparse to abundant.
pinnate with distal leaflets ± distinct, 2–15(–20) × 1–3 cm;
petiole 0.5–5 cm, straight hairs common, tightly appressed, 0.5(–1) mm, stiff, cottony hairs absent, glands absent or sparse;
primary lateral leaflets (3–)4–6(–8) per side, on distal (1/4–)1/2–3/4 of leaf axis, overlapping to separate, largest ones obovate, 0.5–1.5(–2) × 0.5–1(–1.3) cm, distal (1/2–)2/3 to whole margin pinnately incised 3/4+ to midvein, ultimate teeth 5–10, linear-oblanceolate, 1.5–8(–10) × 1–2 mm, apical tufts less than 0.5 mm, surfaces green to grayish green, not glaucous, straight hairs sparse to common (sparser adaxially), tightly appressed, 0.5 mm, stiff, cottony hairs absent, glands absent or inconspicuous.
1–3.
(1–)3–15(–20)-flowered, loosely cymose, sometimes racemiform.
1–4(–5) cm, ± recurved in fruit.
epicalyx bractlets broadly lanceolate to elliptic, 1.5–4(–5) × (0.4–)0.8–1.3 mm;
sepals 2–4(–5) mm, apex ± acute;
petals (3–)4–6 × (2–)3–5 mm;
filaments 1–2(–2.5) mm, anthers 0.4–0.6 mm;
carpels 20–50.
epicalyx bractlets narrowly elliptic to linear-lanceolate, 2–5(–6) × 0.5–2 mm;
hypanthium 3–4 mm diam.;
sepals 3–6 mm, apex acute;
petals 4–7 × 3–6 mm;
filaments 1–2.5 mm, anthers 0.5–1 mm, usually ± 1/2 as long as filaments;
carpels 10–20, styles 1.5–2.5 mm.
0.9–1.2 mm.
(1.3–)1.5–1.9 mm, smooth, often ± carunculate.
= 70.
Potentilla newberryi
Potentilla plattensis
Potentilla newberryi grows in valley bottoms in south-central Oregon, northeastern California, and northwestern Nevada. The only specimen supposedly collected in south-central Washington (W. N. Suksdorf 2718, WTU) was gathered in 1898.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Potentilla plattensis occurs mostly east of the Continental Divide from the Canadian Prairies to the mountains of New Mexico. The species barely enters Idaho at Monida Pass (Clark County). Populations also exist in the White Mountains of east-central Arizona and the mountains of southern Utah. The species is relatively uniform throughout its range but there is often significant seasonal variation, such that plants can be compact and densely strigose in early summer but elongate and subglabrous later in the season.
Where the ranges of Potentilla plattensis and P. ovina overlap, the two are sometimes difficult to distinguish. The habitats are usually distinct, in that P. plattensis generally occurs in moist valley bottoms and P. ovina occurs in rocky uplands. Differences in vestiture are also diagnostic: hairs of P. plattensis are 0.5 mm and tightly appressed; those of P. ovina are longer and looser.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
- Local floras:
CA, 
OR, 
WA - Local Web sites: CalFlora, CalPhotos,
Flora NW, 
PNW Herbaria 
WildflowerSearch
iNaturalist (observations)
USDA Plants Database- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
SW CO Wildflowers
