Potentilla plattensis
Potentilla pulchella
Platte cinquefoil, Platte River cinquefoil
potentille jolie, pretty 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.
ascending, 0.1–1.5(–2) dm.
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.
subpinnate, 1.5–9 cm;
petiole 0.7–4 cm, long hairs common to dense, ± appressed to ascending, 0.5–3 mm, soft, short hairs absent, crisped hairs sparse to abundant, glands absent or sparse;
leaflets (1–)2(–3) per side, on distal 1/6–1/2 of leaf axis, separate to overlapping, terminal ones oblong or obovate, 0.4–3 × 0.2–1.2 cm, margins revolute, incised 2/3–3/4+ to midvein, undivided medial blade 2–6 mm wide, teeth 2–5 per side, linear to narrowly oblong, surfaces dissimilar, abaxial white, long hairs ± abundant, 1–2 mm, soft, short hairs absent or obscured, crisped and/or cottony hairs dense, glands absent or obscured, adaxial grayish white to dark grayish green, long hairs sparse to dense, loosely appressed to spreading, 0.5–2 mm, short hairs absent, crisped hairs absent or sparse, glands absent.
1–3.
1–2.
(1–)3–15(–20)-flowered, loosely cymose, sometimes racemiform.
(1–)2–5(–9)-flowered, ± open.
1–4(–5) cm, ± recurved in fruit.
0.5–1 cm (proximal to 5 cm).
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.
epicalyx bractlets oblong to ovate, 2–4(–6) × 0.8–1.3(–2) mm, lengths ± 3/4 times sepals, margins sometimes revolute;
hypanthium 2.5–4 mm diam.;
sepals 3–5 mm, apex obtuse to subacute, abaxial surfaces: venation indistinct, glands ± abundant, often obscured;
petals pale yellow, 4–5 × 2–3 mm, lengths 1.5 times sepals;
filaments 1–1.5 mm, anthers 0.4 mm;
carpels 30–60, styles papillate-swollen in proximal 1/4–1/3, 0.9–1.2 mm.
(1.3–)1.5–1.9 mm, smooth, often ± carunculate.
1.4–1.5 mm, smooth or rugose.
= 70.
= 28.
Potentilla plattensis
Potentilla pulchella
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.)
Potentilla pulchella is morphologically isolated within sect. Pensylvanicae and is very polymorphic. The proposed races (var. elatior, subsp./var. gracilicaulis) differ only in characters appearing throughout the range of the species (more slender and erect to ascending stems, less hairy leaves). Some different morphs are often found close together but in different habitats.
Some species with palmate or subpalmate leaves combine features of Potentilla pulchella and species from sect. Niveae (addressed under 8t. sect. Rubricaules); others are possible hybrids between P. hyparctica and P. pulchella (sect. Aureae).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
OR
Flora NW
PNW Herbaria
SW CO Wildflowers
WildflowerSearch
iNaturalist
USDA Plants Database
