Potentilla bipinnatifida |
Potentilla johnstonii |
|
---|---|---|
bipinnate cinquefoil, potentille bipinnatifide, tansy cinquefoil |
sagebrush cinquefoil |
|
Stems | ascending to erect, (1–)2–5 dm. |
0.4–2 dm, lengths 2 times basal leaves. |
Basal leaves | subpinnate to subpalmate, (6–)10–25 cm; petiole (2–)5–15 cm, long hairs dense, appressed, 1–2 mm, soft to ± stiff, short hairs absent, crisped hairs sparse, glands absent, sparse, or obscured; leaflets 2–3 per side, on distal 1/6–1/3(–1/2) of leaf axis, separate to ± overlapping, terminal ones oblanceolate, (2–)3–6(–10) × 1–2(–3.5) cm, margins revolute, incised 3/4+ to midvein, undivided medial blade 1.5–6 mm wide, teeth 5–8 per side, ± linear, surfaces ± to strongly dissimilar, abaxial usually white, rarely grayish, long hairs abundant especially on veins, 1–2 mm, ± weak, short hairs absent or obscured, cottony (and crisped) hairs ± dense, glands absent or obscured, adaxial green to grayish, long hairs sparse to abundant, loosely appressed, 0.5–1.5 mm, short hairs absent or sparse, crisped and/or cottony hairs sparse to common, glands sparse to common. |
palmate, 3–8(–13) cm; petiole 1.5–5(–8) cm, straight hairs abundant, ± appressed, 1–2 mm, stiff, cottony hairs absent, glands sparse to abundant; leaflets (3–)5–7(–9), on tip or at least less than distal 1/10 of leaf axis, separate to slightly overlapping, proximal pair separated from others by 0–1 mm of leaf axis, central leaflets narrowly cuneate to oblanceolate, 1–3(–4) × 0.3–0.7 cm, petiolule 1 mm, distal 1/4 or less of margins incised 1/3–2/3 to midvein, teeth 1(–3) per side, separate, 1–2(–4) mm, surfaces similar, green to grayish, straight hairs sparse to common, appressed, 1–1.5(–2) mm, stiff (sometimes softer and wavy), cottony hairs absent, glands sparse to abundant. |
Cauline leaves | 2–4. |
|
Inflorescences | (4–)10–50(–100)-flowered, congested or elongating in fruit. |
4–11-flowered. |
Pedicels | 0.2–0.8 cm (proximal to 2 cm). |
0.7–2(–4) cm. |
Flowers | epicalyx bractlets narrowly elliptic to lanceolate, 2.5–6 mm, lengths ± 2/3 times sepals, margins flat; hypanthium 3–5 mm diam.; sepals 3–6 mm, apex ± acute, abaxial surfaces: venation indistinct, glands absent, sparse, or obscured; petals yellow, 3–5 × 3–4 mm, lengths ± equal to sepals; filaments 0.5–2 mm, anthers 0.3–0.5 mm; carpels 50–80, styles papillate-swollen in proximal 1/2–3/4+, 1–1.2 mm. |
epicalyx bractlets ± lanceolate, 2–4 × 1 mm; hypanthium 3–4(–6) mm diam.; sepals 3–4.5 mm, apex acute to obtuse; petals 5–7 × 3–5 mm; filaments 1–2.5 mm, anthers 0.6–0.8 mm; carpels 3–10, styles 2–2.5 mm. |
Achenes | 1–1.2 mm, smooth to faintly rugose. |
2.5 mm, smooth to slightly rugose. |
2n | = 56. |
|
Potentilla bipinnatifida |
Potentilla johnstonii |
|
Phenology | Flowering summer. | Flowering summer. |
Habitat | Open shortgrass prairie, alkaline bottoms, streamsides in sagebrush, disturbed sites | Rocky slopes in pinyon-juniper woodlands, with Artemisia |
Elevation | 10–3400 m (0–11200 ft) | 2300–2500 m (7500–8200 ft) |
Distribution |
AK; CO; ID; MI; MN; MT; ND; NE; NM; SD; UT; WY; AB; MB; NT; ON; QC; SK; YT
|
NV |
Discussion | Potentilla bipinnatifida is similar to P. litoralis in habit and leaf dissection but has flat, silky epicalyx bractlets and sepals with no evident glands. Vestiture is generally silkier, and the silvery to bicolor leaves are white-cottony abaxially. The two species are sympatric in the plains of Canada, with some intergradation; P. bipinnatifida is also common south to Colorado, where it is found in intermontane meadows and sagebrush flats. Outlying populations occur in Blaine and Custer counties, Idaho, and Duchesne and Piute counties, Utah. Eastern collections from disturbed sites might be adventive. Potentilla missourica Hornemann ex Lindley and P. normalis Besser ex Sprengel are older names for this species; both were rejected against a conserved P. bipinnatifida with designated lectotypes (see J. Soják 2008b). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. Potentilla johnstonii occurs only in the Quinn Canyon Range in Nye County. Its distinctiveness was first noted by B. C. Johnston (1980), who treated it as a variety of P. concinna using the unpublished epithet curvata. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 9, p. 217. | FNA vol. 9, p. 182. |
Parent taxa | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Pensylvanicae | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Concinnae |
Sibling taxa | ||
Synonyms | P. pensylvanica var. bipinnatifida | |
Name authority | Douglas: in W. J. Hooker, Fl. Bor.-Amer. 1: 188. (1832) | Soják: Thaiszia 16: 97. (2007) |
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