Potentilla simplex |
Potentilla biennis |
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common cinquefoil, old-field cinquefoil, old-field five-fingers, potentille simple, simple cinquefoil |
biennial cinquefoil, biennial or Greene's cinquefoil, Greene's cinquefoil |
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Stems | initially erect to ascending to 5 dm, then arching above ground-level, becoming prostrate, flagelliform, not branched, rooting at distal nodes, (0.5–)1.5–12 dm. |
ascending to erect, (1–)2–6(–8.5) dm, hairs at base not stiff, not tubercle-based, glands sparse to abundant, conspicuous (to 1 mm, septate). |
Leaves | ternate, (2–)4–12(–25) cm; petiole (1–)2–8(–20) cm, long hairs sparse to common, spreading to ascending, 0.5–1.5(–3) mm, weak, crisped hairs usually absent, glands sparse to abundant, conspicuous (to 1 mm, septate); leaflets 3, at tip of leaf axis, usually overlapping, largest ones mostly obovate or oval to nearly round, (0.5–)1–3(–4) × 0.3–3(–3.5) cm, distal 3/4 to ± whole margin evenly to unevenly incised 1/4–1/3(–1/2) to midvein, teeth 3–8(–13) per side, surfaces sparsely to moderately hairy, rarely glabrate, glands sparse to abundant at least abaxially. |
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Basal leaves | persistent or ephemeral, usually palmate, 3.5–20 cm; petiole 1–15 cm, long hairs ± abundant, appressed to spreading, (0.5–)1–3 mm, weak to ± stiff, glands absent or sparse, sometimes common; leaflets 5(–7), central narrowly elliptic to obovate, 1.5–5 × 0.5–2.5 cm, distal 1/2–3/4 of margin incised 1/4–1/3 to midvein, teeth 4–8(–13) per side, surfaces similar to ± dissimilar, abaxial green to silvery white, sparsely to abundantly hairy, adaxial green, glabrate or sparsely to moderately hairy. |
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Cauline leaves | (0–)1 proximal to 1st flowering node, well expanded at anthesis, usually palmate, 2.5–6(–9) cm; petiole 0–2(–4) cm; leaflets (3–)5, often more elongate than those of basal leaves, ± elliptic to oblanceolate, sometimes obovate, 1.5–6(–7.5) × 0.5–2(–3) cm, apex acute to obtuse. |
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Inflorescences | solitary flowers at stolon nodes. |
(10–)20–70+-flowered. |
Pedicels | 1–5(–8.5) cm. |
0.2–1(–2) cm. |
Flowers | 5(–6)-merous; epicalyx bractlets linear to narrowly lanceolate, 2–5 × 1–1.5(–2) mm, often larger than sepals (especially in bud); hypanthium 3–5 mm diam.; sepals 4–6 mm, apex broadly acute; petals 4–7 × 3–6 mm, apex rounded to ± retuse; stamens ca. 20, filaments 0.5–2 mm, anthers 0.6–1 mm; carpels 20–50, styles 0.8–1.5 mm. |
epicalyx bractlets narrowly oblanceolate to narrowly obovate or elliptic, (1.5–)2–3.5(–4.5) × 0.5–1.5(–2) mm; hypanthium (2–)3–4(–5.5) mm diam.; sepals (2–)3–5 mm, apex broadly acute to obtuse; petals pale yellow to yellow, broadly oblanceolate to obovate, (1–)2–2.7 × 1.5 mm; stamens 10 or 15, filaments 0.5–1.2 mm, anthers 0.2–0.3 mm; carpels 40–100, styles 0.5–0.7 mm. |
Achenes | 0.9–1.2 mm, faintly rugose. |
whitish or pale yellowish, 0.5–0.9 mm, smooth, without a corky protuberance. |
Rootstocks | horizontal, irregularly thickened or moniliform, 1–8 cm. |
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Potentilla simplex |
Potentilla biennis |
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Phenology | Flowering (Mar–)Apr–Jul(–Aug). | Flowering summer. |
Habitat | Dry or infrequently moist flats and slopes in pastures, dry meadows, roadsides, old fields, edges of mixed oak and conifer woodlands, often on acidic soil | Moist meadows, stream banks, ditches, seepages |
Elevation | 0–800 m (0–2600 ft) | 400–3100 m (1300–10200 ft) |
Distribution |
AL; AR; CT; DC; DE; GA; IA; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; NC; NE; NH; NJ; NY; OH; OK; PA; RI; SC; TN; TX; VA; VT; WI; WV; NB; NF; NS; ON; PE; QC; SPM
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AK; AZ; CA; CO; ID; MT; ND; NM; NV; OR; UT; WA; WY; AB; BC; SK; YT
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Discussion | The distinction between Potentilla simplex and P. canadensis is subtle, and the former is often misidentified as the latter; additional features to distinguish the two species are provided by M. L. Fernald (1931). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Potentilla biennis may be recognized by its septate hairs with a round, terminal gland, which dominate the vestiture especially at the base of the plant. Stems are more commonly erect and leaflets rounder than those of P. rivalis. The species is most common along the eastern side of the Sierra Nevada of California, across the Intermountain Region to the Rocky Mountains. All specimens seen by the authors from Baja California, Mexico, which were previously referred to P. biennis are now assigned to P. rivalis. J. Soják (1996) lectotypified Potentilla millegrana Engelmann ex Lehmann upon a collection of P. rivalis, thus preventing P. biennis from being a later taxonomic synonym. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 9, p. 134. | FNA vol. 9, p. 140. |
Parent taxa | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Potentilla | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Rivales |
Sibling taxa | ||
Synonyms | P. canadensis var. simplex, P. simplex var. argyrisma, P. simplex var. calvescens | |
Name authority | Michaux: Fl. Bor.-Amer. 1: 303. (1803) | Greene: Fl. Francisc., 65. (1891) |
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