39. Potentilla ovina J. M. Macoun, Canad. Rec. Sci. 6: 464. 1896.
Sheep cinquefoil
Potentilla diversifolia Lehmann var. pinnatisecta S. Watson, Botany (Fortieth Parallel), 87. 1871; P. pinnatisecta (S. Watson) A. Nelson; P. plattensis Nuttall var. pinnatisecta (S. Watson) J. M. Macoun
Plants rosetted to ± matted; taproots sometimes ± fleshy-thickened. Stems prostrate to ascending, (0.3–)0.8–2(–3.5) dm, lengths (1–)1.5–3 times basal leaves. Basal leaves pinnate with distal leaflets ± distinct, (1.5–)2–10(–13) × 0.7–3.5(–5) cm; petiole 0.5–3.5(–5) cm, straight hairs sparse to abundant, sometimes absent (var. decurrens), ± appressed to ascending, 1 mm, ± stiff, cottony hairs absent, glands sparse, often obscured; primary lateral leaflets 3–6 per side (often with additional interspersed leaflets), on distal 1/2–2/3(–3/4) of leaf axis, ± separate to ± overlapping, largest ones narrowly cuneate-oblanceolate to ± obovate, (0.3–)0.5–2(–3.5) × (0.2–)0.3–0.8(–1) cm, distal 1/4 to whole margin unevenly to pinnately (at least distal leaflets of var. ovina) incised 1/2–3/4+ to midvein, ultimate teeth 2–9(–11), linear or oblong to ovate, 1–7(–9) × 1–2 mm, apical tufts 0.5–2 mm, surfaces green to grayish, not glaucous, straight hairs sparse to abundant (sparser adaxially), sometimes absent (except on margins), loosely appressed, 0.5–2 mm, ± stiff, cottony hairs absent, ˂crisped hairs sometimes sparse to common˃, glands absent or inconspicuous. Cauline leaves 1–2. Inflorescences (1–)2–11(–20)-flowered, usually openly cymose. Pedicels (0.8–)1–2(–4) cm, straight to ± recurved in fruit. Flowers: epicalyx bractlets linear-lanceolate to narrowly elliptic, ˂sometimes doubled˃, 2–3.5(–5) × 1 mm; hypanthium 3–5 mm diam.; sepals 3.5–5.5(–7) mm, apex acute to obtuse; petals 4–7(–8) × 3.5–8 mm; filaments 1–2.5 mm, anthers 0.4–1 mm ˂usually ± 1/2 as long as filaments˃; carpels 10–20, styles 2–3 mm. Achenes 1.5–2 mm, smooth, not carunculate.
Varieties 2 (2 in the flora): w North America.
Potentilla ovina is here accepted as an implicit new name by J. M. Macoun for P. diversifolia var. pinnatisecta, in agreement with N. H. Holmgren (1997b). In contrast, B. C. Johnston (1980) considered the names heterotypic. Potentilla ovina has priority at the species rank over P. pinnatisecta by one month.