Potentilla versicolor |
Potentilla vahliana |
|
---|---|---|
Steens Mountain cinquefoil, varying cinquefoil |
potentille de Vahl, Vahl's cinquefoil |
|
Habit | Plants rosetted to ± matted; taproots ± fleshy-thickened. | Plants densely tufted to cushion-forming. |
Caudex branches | usually stout, columnar, sheathed with marcescent whole leaves. |
|
Stems | prostrate to ascending, (0.7–)1.5–2.5(–4) dm, lengths 2–4(–5) times basal leaves. |
erect, (0.2–)0.3–0.8(–1) dm, lengths 2–4(–5) times basal leaves. |
Basal leaves | pinnate with distal leaflets ± confluent, 4–12 × 1–2.5(–3.5) cm; petiole 1–3 cm, straight hairs absent (on early-season petioles) or sparse to common, spreading-ascending to loosely appressed, 1–2 mm, soft, cottony hairs usually absent, glands sparse; primary lateral leaflets 3–5 per side, on distal (1/3–)1/2–2/3 of leaf axis, overlapping, largest ones cuneate to flabellate, 0.5–1.5(–2) × 0.5–1.5 cm, distal 3/4 to whole margin unevenly incised 2/3 to completely to midvein (blade often medially split as well), ultimate teeth or segments 2–5(–8), ± oblanceolate, 3–11 × 1–3 mm, apical tufts to 1 mm, surfaces green to grayish green, not glaucous, straight hairs sparse to common (sparser adaxially), sometimes absent (except on margins), loosely appressed to ascending, 1–2 mm, soft, cottony hairs absent, glands sparse to common. |
1–3 cm; petiole 0.5–2 cm, long hairs common to abundant, ascending to spreading, 0.5–1.5(–2) mm, soft to weak, smooth, short hairs absent, crisped/short-cottony hairs sparse to abundant, glands sparse to common; leaflets separate to slightly overlapping, central obovate, 0.8–1.2(–1.5) × 0.5–1(–1.5) cm, sessile or subsessile, base cuneate, margins revolute, distal ± 1/2 incised (1/3–)1/2–3/4 to midvein, teeth 2–3 per side, ± approximate to distant, surfaces ± dissimilar, abaxial yellowish white or grayish, long hairs 1–2 mm, cottony-crisped hairs ± dense, adaxial green to yellowish gray, long(/short) hairs common to abundant, crisped hairs absent or sparse. |
Cauline leaves | 1–2(–3). |
0–1(–2). |
Inflorescences | (1–)3–10-flowered, usually openly cymose. |
1–2(–3)-flowered. |
Pedicels | 1–3(–5) cm, straight to slightly recurved in fruit. |
0.5–1.5 cm in flower, to 3.5 cm in fruit. |
Flowers | epicalyx bractlets lanceolate to elliptic, rarely ovate, 2–5 × 1–2 mm, sometimes apically toothed; hypanthium 3–5 mm diam.; sepals 4–7 mm, apex acute; petals 4–7 × 3–5.5 mm; filaments (1–)1.5–2.5 mm, anthers 0.5–0.8 mm; carpels 10–25, styles 2 mm. |
epicalyx bractlets broadly ovate, 2.5–4(–5) × 1.5–3 mm, ± as wide as sepals, margins flat or revolute, red glands absent; hypanthium 2–4 mm diam.; sepals 2.5–5(–6) mm, apex subacute to acute; petals 8–10 × 7–12 mm, significantly longer than sepals; filaments 1–1.2 mm, anthers 0.4–0.6 mm; carpels 30–40, apical hairs absent, styles narrowly columnar, distinctly papillate-swollen at very base, 1–1.1 mm. |
Achenes | 1.5–1.8 mm, smooth to faintly rugose, not carunculate. |
1.1–1.5 mm. |
2n | = 42, 49, 56. |
|
Potentilla versicolor |
Potentilla vahliana |
|
Phenology | Flowering summer. | Flowering summer. |
Habitat | Rocky, alpine meadows, seasonally moist slopes, near streams or snowmelt | Gravelly dry tundra, dry ridges, gravel flats, herb slopes, acidic and calcareous bedrock |
Elevation | 2100–3200 m (6900–10500 ft) | 0–700 m (0–2300 ft) |
Distribution |
NV; OR
|
NU; QC; Greenland |
Discussion | Potentilla versicolor is most common on Steens Mountain in Harney County, Oregon. Collections are known from other mountain ranges in eastern Oregon (some possibly representing distinct taxa) and from near Island Lake in the Ruby Mountains of northeastern Nevada. The species often grows and, apparently, intergrades with P. breweri; it is usually distinct in its lack of cottony hairs. Petals, filaments, and styles tend to be somewhat shorter in P. versicolor than in P. breweri. Collections of P. versicolor have most often been identified as P. breweri, P. millefolia, or P. ovina. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
As circumscribed here, Potentilla vahliana is confined to northeastern arctic Canada (including northernmost Quebec) and western Greenland. Plants previously assigned to P. vahliana from northwestern Greenland, Yukon, most of arctic Canada, and Alaska are now relegated to P. subvahliana. Plants from western Greenland, whence Potentilla vahliana was described and typified, have petioles with at least some short cottony or crisped hairs in addition to long, smooth hairs, and the styles have distinct papillae at the very base. These features are derived from a combination of the P. uniflora Ledebour and P. nivea groups. Potentilla vahliana is of a higher polyploidy than the species of the P. uniflora group. Potentilla vahliana is treated here as a geographically restricted species, most probably from cross(es) between P. nivea in the narrow sense (probably the Atlantic race, often 2n = 70) and P. subvahliana (2n = 28); it shares several features with the latter, not least of which is leaf dissection and the columnar structure of the caudex. In mainland Quebec, plants combine features from Potentilla arenosa and P. vahliana; that is, the straight hairs are slightly verrucose, not smooth as in P. nivea, P. subvahliana, and P. vahliana in the narrow sense. They form populations and probably should be described as a new hybrid species. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 9, p. 171. | FNA vol. 9, p. 205. |
Parent taxa | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Multijugae | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Niveae |
Sibling taxa | ||
Synonyms | P. hirsuta | |
Name authority | Rydberg: in N. L. Britton et al., N. Amer. Fl. 22: 344. (1908) | Lehmann: Monogr. Potentill., 172. (1820) — not Michaux 1803 |
Web links |