Potentilla bipinnatifida |
Potentilla subvahliana |
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bipinnate cinquefoil, potentille bipinnatifide, tansy cinquefoil |
high arctic cinquefoil |
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Habit | Plants usually cushion-forming. | |
Caudex branches | stout, columnar, sheathed with marcescent whole leaves. |
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Stems | ascending to erect, (1–)2–5 dm. |
erect, 0.2–0.6(–1.1) dm, lengths 2–4 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. |
0.5–2.5(–3) cm; petiole 0.3–1.5(–2) cm, long hairs common to abundant, spreading to ascending, 1(–2) mm, ± weak, rarely stiff, smooth, crisped/short-cottony hairs usually absent, sometimes sparse, glands sparse to common; leaflets separate to slightly overlapping, central obovate, 0.5–1.2(–1.5) × 0.4–0.9(–1) cm, subsessile to short-petiolulate, base cuneate, margins revolute, distal 1/2 incised 1/2–3/4 to midvein, teeth (1–)2–3(–4) per side, ± distant, surfaces ± dissimilar, abaxial grayish or yellowish white, long hairs 0.5–1 mm, cottony-crisped hairs ± dense (often obscured by long hairs), adaxial dark green to greenish gray, long hairs ± abundant, other hairs absent. |
Cauline leaves | 2–4. |
(0–)1(–2). |
Inflorescences | (4–)10–50(–100)-flowered, congested or elongating in fruit. |
1(–2)-flowered. |
Pedicels | 0.2–0.8 cm (proximal to 2 cm). |
1–2(–3) cm in flower, to 5.5 cm in fruit. |
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 to elliptic-ovate, rarely linear, 3–6(–7) × 0.8–2(–2.3) mm, (1/2–)2/3 to nearly as wide as sepals, margins flat or ± revolute, red glands absent; hypanthium 2.5–4 mm diam.; sepals 3–5(–6) mm, apex obtuse to subacute; petals 4–8(–9) × 4–9 mm, longer than sepals; filaments 1–1.3 mm, anthers 0.3–0.5 mm; carpels 25–35, apical hairs absent, styles conic-columnar, ± papillate-swollen on less than proximal 1/5, 0.9–1.1 mm. |
Achenes | 1–1.2 mm, smooth to faintly rugose. |
1.2–1.6 mm. |
2n | = 56. |
= 28 (Russian Far East). |
Potentilla bipinnatifida |
Potentilla subvahliana |
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Phenology | Flowering summer. | Flowering late spring to summer. |
Habitat | Open shortgrass prairie, alkaline bottoms, streamsides in sagebrush, disturbed sites | Rocky alpine heaths, rock outcrops and crevices, scree and talus, dry tundra, coastal bluffs, stabilized sand dunes, usually on calcareous bedrock |
Elevation | 10–3400 m (0–11200 ft) | 0–1700 m (0–5600 ft) |
Distribution |
AK; CO; ID; MI; MN; MT; ND; NE; NM; SD; UT; WY; AB; MB; NT; ON; QC; SK; YT
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AK; AB; BC; NT; NU; QC; YT; Greenland; e Asia (Russian Far East) |
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.) |
The major part of the range assigned to Potentilla vahliana by E. Hultén (1968) belongs to P. subvahliana. Two morphologic types are present within what is accepted here as Potentilla subvahliana. Plants corresponding to the type of P. subvahliana (Wrangel Island) are widespread throughout northeastern Asia (Chukotka) and arctic North America to northwestern Greenland. Some plants in alpine Alaska, Yukon, and east to Amundsen Gulf, Nunavut, are redder, more densely columnar, and less hairy, with smaller leaves having fewer and narrower lobes, more slender one-flowered stems, narrow and entire bracts, narrower sepals, and much narrower epicalyx bractlets. Potentilla subvahliana is tetraploid, perhaps an allopolyploid, and could consist of lineages from different parental combinations. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 9, p. 217. | FNA vol. 9, p. 203. |
Parent taxa | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Pensylvanicae | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Niveae |
Sibling taxa | ||
Synonyms | P. pensylvanica var. bipinnatifida | |
Name authority | Douglas: in W. J. Hooker, Fl. Bor.-Amer. 1: 188. (1832) | Jurtzev: in A. I. Tolmatchew, Fl. Arct. URSS 9(1): 319. (1984) |
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