Potentilla subvahliana |
Potentilla plattensis |
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high arctic cinquefoil |
Platte cinquefoil, Platte River cinquefoil |
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Habit | Plants usually cushion-forming. | Plants rosetted to tufted; taproots fleshy-thickened. |
Caudex branches | stout, columnar, sheathed with marcescent whole leaves. |
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Stems | erect, 0.2–0.6(–1.1) dm, lengths 2–4 times basal leaves. |
initially decumbent to sometimes ascending, becoming prostrate or supported by vegetation, (0.3–)0.5–3.5(–4.5) dm, lengths 1.5–2.5(–4) times basal leaves. |
Basal leaves | 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. |
pinnate with distal leaflets ± distinct, 2–15(–20) × 1–3 cm; petiole 0.5–5 cm, straight hairs common, tightly appressed, 0.5(–1) mm, stiff, cottony hairs absent, glands absent or sparse; primary lateral leaflets (3–)4–6(–8) per side, on distal (1/4–)1/2–3/4 of leaf axis, overlapping to separate, largest ones obovate, 0.5–1.5(–2) × 0.5–1(–1.3) cm, distal (1/2–)2/3 to whole margin pinnately incised 3/4+ to midvein, ultimate teeth 5–10, linear-oblanceolate, 1.5–8(–10) × 1–2 mm, apical tufts less than 0.5 mm, surfaces green to grayish green, not glaucous, straight hairs sparse to common (sparser adaxially), tightly appressed, 0.5 mm, stiff, cottony hairs absent, glands absent or inconspicuous. |
Cauline leaves | (0–)1(–2). |
1–3. |
Inflorescences | 1(–2)-flowered. |
(1–)3–15(–20)-flowered, loosely cymose, sometimes racemiform. |
Pedicels | 1–2(–3) cm in flower, to 5.5 cm in fruit. |
1–4(–5) cm, ± recurved in fruit. |
Flowers | 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. |
epicalyx bractlets narrowly elliptic to linear-lanceolate, 2–5(–6) × 0.5–2 mm; hypanthium 3–4 mm diam.; sepals 3–6 mm, apex acute; petals 4–7 × 3–6 mm; filaments 1–2.5 mm, anthers 0.5–1 mm, usually ± 1/2 as long as filaments; carpels 10–20, styles 1.5–2.5 mm. |
Achenes | 1.2–1.6 mm. |
(1.3–)1.5–1.9 mm, smooth, often ± carunculate. |
2n | = 28 (Russian Far East). |
= 70. |
Potentilla subvahliana |
Potentilla plattensis |
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Phenology | Flowering late spring to summer. | Flowering summer. |
Habitat | Rocky alpine heaths, rock outcrops and crevices, scree and talus, dry tundra, coastal bluffs, stabilized sand dunes, usually on calcareous bedrock | Moist meadows, streamsides, reservoir margins |
Elevation | 0–1700 m (0–5600 ft) | 300–2900 m (1000–9500 ft) |
Distribution |
AK; AB; BC; NT; NU; QC; YT; Greenland; e Asia (Russian Far East) |
AZ; CO; ID; MT; ND; NM; SD; UT; WY; AB; MB; NT; SK
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Discussion | 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.) |
Potentilla plattensis occurs mostly east of the Continental Divide from the Canadian Prairies to the mountains of New Mexico. The species barely enters Idaho at Monida Pass (Clark County). Populations also exist in the White Mountains of east-central Arizona and the mountains of southern Utah. The species is relatively uniform throughout its range but there is often significant seasonal variation, such that plants can be compact and densely strigose in early summer but elongate and subglabrous later in the season. Where the ranges of Potentilla plattensis and P. ovina overlap, the two are sometimes difficult to distinguish. The habitats are usually distinct, in that P. plattensis generally occurs in moist valley bottoms and P. ovina occurs in rocky uplands. Differences in vestiture are also diagnostic: hairs of P. plattensis are 0.5 mm and tightly appressed; those of P. ovina are longer and looser. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 9, p. 203. | FNA vol. 9, p. 173. |
Parent taxa | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Niveae | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Multijugae |
Sibling taxa | ||
Synonyms | P. diversifolia var. madsenii, P. plattensis var. pedicillata | |
Name authority | Jurtzev: in A. I. Tolmatchew, Fl. Arct. URSS 9(1): 319. (1984) | Nuttall: in J. Torrey and A. Gray, Fl. N. Amer. 1: 439. (1840) |
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