Potentilla plattensis
Potentilla intermedia
Platte cinquefoil, Platte River cinquefoil
downy cinquefoil, potentille intermédiaire
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 to erect, 2–5 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.
palmate or ternate.
1–3.
3–8, proximal ones (3–)5–14 cm;
proximal petioles (1–)2–10 cm, long hairs sparse to common, spreading to loosely appressed, 1–2 mm, weak, short or crisped hairs sparse to common, cottony hairs absent, glands absent or sparse;
leaflets usually 5, central one oblanceolate to obovate, 2–4.5 × 1–2.5 cm, margins ± flat, distal 3/4+ usually unevenly, sometimes evenly, incised 1/3–2/3 to midvein (often with 1–2 incisions nearly to midvein), teeth 5–10 per side, surfaces similar or ± dissimilar, abaxial green to grayish green, long hairs sparse to common (especially on veins), 0.5–1.5 mm, soft to weak, short or crisped hairs ± sparse, cottony hairs absent, glands absent or sparse, adaxial long hairs absent or sparse, 1 mm, short hairs absent or sparse, crisped and cottony hairs absent, glands absent or sparse.
(1–)3–15(–20)-flowered, loosely cymose, sometimes racemiform.
20–100+-flowered.
1–4(–5) cm, ± recurved in fruit.
0.5–1.5(–2.5) 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 lanceolate to ovate or elliptic, 2–5 × 0.8–1.5 mm, lengths usually 2/3, sometimes 1, times sepals;
sepals 3.5–6.5 mm, apex ± acute;
petals 3–5 × 2–3 mm;
filaments 0.8–2 mm, anthers 0.3–0.5 mm;
carpels 40–70, styles 1–1.2 mm, scarcely papillate-swollen proximally.
(1.3–)1.5–1.9 mm, smooth, often ± carunculate.
1 mm, rugose.
= 70.
= 28, 56 (Eurasia).
Potentilla plattensis
Potentilla intermedia
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 intermedia is more common than P. inclinata at least in eastern Canada and New England.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
OR
Flora NW
PNW Herbaria
SW CO Wildflowers
WildflowerSearch
iNaturalist
USDA Plants Database
Go Botany
MI Flora
