Potentilla biennis |
Potentilla sierrae-blancae |
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biennial cinquefoil, biennial or Greene's cinquefoil, Greene's cinquefoil |
Sierra blanca cinquefoil |
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Stems | 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). |
0.2–1 dm, lengths 1–1.5 times basal leaves. |
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 | palmate, 2–8 cm; petiole 0.5–5 cm, straight hairs sparse to abundant, sometimes absent, ± appressed, 2–3 mm, usually ± stiff, cottony hairs absent, glands absent; leaflets (3–)4–5, at tip of leaf axis, separate, proximal pair separated from others by 0(–1) mm of leaf axis, central leaflets narrowly cuneate-oblanceolate, 0.8–2.2 × 0.2–0.5 cm, petiolules 0(–1) mm, less than distal 1/4 of margins incised 1/2–3/4 to midvein, teeth 1(–2) per side, ± separate, 1–2 mm, surfaces similar, green, straight hairs mostly absent (except on margins), appressed, 1–2 mm, stiff, cottony hairs absent, glands absent, rarely sparse. |
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Inflorescences | (10–)20–70+-flowered. |
solitary flowers or 2–3-flowered. |
Pedicels | 0.2–1(–2) cm. |
1–4 cm. |
Flowers | 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. |
epicalyx bractlets narrowly to widely elliptic-ovate, 2–3.5 × 1–1.5 mm; hypanthium 3–5 mm diam.; sepals 3–5 mm, apex obtuse to acute; petals 5–7 × 4–6 mm; filaments 1–2 mm, anthers 0.4–0.8 mm; carpels 5–20, styles 2 mm. |
Achenes | whitish or pale yellowish, 0.5–0.9 mm, smooth, without a corky protuberance. |
1.5 mm, smooth. |
Potentilla biennis |
Potentilla sierrae-blancae |
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Phenology | Flowering summer. | Flowering summer. |
Habitat | Moist meadows, stream banks, ditches, seepages | Windswept barren ridges, subalpine grasslands, rock outcrops |
Elevation | 400–3100 m (1300–10200 ft) | 2400–3700 m (7900–12100 ft) |
Distribution |
AK; AZ; CA; CO; ID; MT; ND; NM; NV; OR; UT; WA; WY; AB; BC; SK; YT
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NM |
Discussion | 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.) |
Of conservation concern. Potentilla sierrae-blancae is restricted to the White Mountains, Lincoln and Otero counties. P. A. Rydberg (1898, 1908d) and B. C. Johnston (1985) placed P. sierrae-blancae in sect. (or group) Aureae; the species fits well in sect. Concinnae, combining the few-flowered inflorescence of P. angelliae with the tridentate leaflets of P. bicrenata and P. johnstonii. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 9, p. 140. | FNA vol. 9, p. 182. |
Parent taxa | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Rivales | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Concinnae |
Sibling taxa | ||
Name authority | Greene: Fl. Francisc., 65. (1891) | Wooton & Rydberg: in P. A. Rydberg, Monogr. N. Amer. Potentilleae, 2: 57, plate 18, figs. 3–5. (1898) |
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