Potentilla ovina |
Potentilla villosula |
|||||
---|---|---|---|---|---|---|
sheep cinquefoil |
Alaska cinquefoil, finely villous cinquefoil |
|||||
Habit | Plants rosetted to ± matted; taproots sometimes ± fleshy-thickened. | Plants densely tufted. | ||||
Caudex branches | stout, sometimes ± columnar, not sheathed with marcescent whole leaves. |
|||||
Stems | prostrate to ascending, (0.3–)0.8–2(–3.5) dm, lengths (1–)1.5–3 times basal leaves. |
ascending to erect, 0.2–1.5(–2) dm, lengths 1.5–3(–4) times basal leaves. |
||||
Basal leaves | pinnate with distal leaflets ± distinct, (1.5–)2–10(–13) × 0.7–3.5(–5) cm; petiole 0.5–3.5(–5) cm, straight hairs sparse to abundant, sometimes absent (var. decurrens), ± appressed to ascending, 1 mm, ± stiff, cottony hairs absent, glands sparse, often obscured; primary lateral leaflets 3–6 per side (often with additional interspersed leaflets), on distal 1/2–2/3(–3/4) of leaf axis, ± separate to ± overlapping, largest ones narrowly cuneate-oblanceolate to ± obovate, (0.3–)0.5–2(–3.5) × (0.2–)0.3–0.8(–1) cm, distal 1/4 to whole margin unevenly to pinnately (at least distal leaflets of var. ovina) incised 1/2–3/4+ to midvein, ultimate teeth 2–9(–11), linear or oblong to ovate, 1–7(–9) × 1–2 mm, apical tufts 0.5–2 mm, surfaces green to grayish, not glaucous, straight hairs sparse to abundant (sparser adaxially), sometimes absent (except on margins), loosely appressed, 0.5–2 mm, ± stiff, cottony hairs absent, crisped hairs sometimes sparse to common, glands absent or inconspicuous. |
1–5.5(–7) cm; petiole 0.5–3.5(–5) cm, long hairs common to dense, ascending to spreading, loosely appressed, sometimes retrorse, 1–2(–3) mm, soft, smooth, crisped/short-cottony hairs usually sparse, sometimes common, glands absent or sparse to common or obscured; leaflets overlapping, central broadly obovate to obtriangular, 0.8–2.5 × 0.6–2 cm, sessile to subsessile, base broadly cuneate, margins revolute, distal 1/2–2/3(–3/4) incised ± 1/2 to midvein, teeth 2–3(–4) per side, ± approximate to ± distant, surfaces ± dissimilar, abaxial grayish to white or yellowish white, long hairs 1.5–2.5 mm, cottony-crisped hairs ± dense, adaxial grayish green, long hairs abundant to dense, crisped hairs absent, sparse, or obscured. |
||||
Cauline leaves | 1–2. |
(0–)1–2(–3). |
||||
Inflorescences | (1–)2–11(–20)-flowered, usually openly cymose. |
(1–)2–3(–4)-flowered. |
||||
Pedicels | (0.8–)1–2(–4) cm, straight to ± recurved in fruit. |
0.5–3(–5) cm in flower, to 4(–6) cm in fruit. |
||||
Flowers | epicalyx bractlets linear-lanceolate to narrowly elliptic, sometimes doubled, 2–3.5(–5) × 1 mm; hypanthium 3–5 mm diam.; sepals 3.5–5.5(–7) mm, apex acute to obtuse; petals 4–7(–8) × 3.5–8 mm; filaments 1–2.5 mm, anthers 0.4–1 mm usually ± 1/2 as long as filaments; carpels 10–20, styles 2–3 mm. |
epicalyx bractlets broadly lanceolate to narrowly ovate, 3–7(–8) × 1.5–3(–3.5) mm, 2/3 to as wide as sepals, margins ± revolute, red glands absent; hypanthium (3–)4–6 mm diam.; sepals 4–7(–8) mm, apex acute or rarely acuminate; petals 5–10 × 6–12 mm, significantly longer than sepals; filaments 1.1–1.4 mm, anthers 0.5–0.8 mm; carpels 40–70, apical hairs absent or sparse (straight), styles narrowly columnar to conic-tapered, papillate-swollen in proximal 1/5 or less, 1–1.2 mm. |
||||
Achenes | 1.5–2 mm, smooth, not carunculate. |
0.9–2 mm. |
||||
2n | = 28 (Russian Far East). |
|||||
Potentilla ovina |
Potentilla villosula |
|||||
Phenology | Flowering late spring to summer. | |||||
Habitat | Rocky alpine heaths, outcrops, scree and talus, gravel outwash plains, dry tundra, coastal bluffs, stabilized sand dunes, mostly on acidic bedrock | |||||
Elevation | 0–2900 m (0–9500 ft) | |||||
Distribution |
CO; ID; MT; NV; OR; UT; WY; AB; BC
|
AK; AB; BC; YT; e Asia (Russian Far East) |
||||
Discussion | Varieties 2 (2 in the flora). Potentilla ovina is here accepted as an implicit new name by J. M. Macoun for P. diversifolia var. pinnatisecta, in agreement with N. H. Holmgren (1997b). In contrast, B. C. Johnston (1980) considered the names heterotypic. Potentilla ovina has priority at the species rank over P. pinnatisecta by one month. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Potentilla villosula was included previously in P. villosa; the two overlap in the southern and western Alaskan coasts, where a transition is suspected to be associated with differing ploidy levels. The plants from this area with silky hairs and multiflowered inflorescences are assigned to P. villosa; P. villosula has thicker, stiffer, and less silky hairs, fewer teeth per leaflet, narrower bracts, fewer and smaller flowers with narrower epicalyx bractlets and sepals, and fewer achenes (sometimes with single apical hairs). While P. villosa is restricted to relatively rocky sites near the coast from western Alaska to Oregon, P. villosula often occurs on coastal sand dunes, farther inland, and/or farther to the north. As circumscribed, Potentilla villosula is a major plant of Alaska, especially of the Bering Sea region. The species extends from Alaska and the Yukon to at least central British Columbia. Most of the range given by E. Hultén (1968) for P. villosa belongs to P. villosula. W. J. Cody (1996) accepted the name P. villosula for a common south-central Yukon plant, but the majority of the plants mapped by Cody probably belong to P. subgorodkovii (although the distinction between the two species needs more resolution). Provisionally included here are plants from southern and central Yukon south through the Canadian Rockies, possibly including the type of P. nivea subsp. fallax A. E. Porsild. Such plants tend to be significantly smaller overall than Alaskan P. villosula; at least some have straight hairs on carpel apices. J. Soják (2004) believed that Potentilla villosula evolved from crosses between P. villosa and P. vulcanicola. The affinity with P. villosa is seen in the sericeous vestiture, number of leaflet teeth, and flower number and size, and with P. vulcanicola in the frequent occurrence of straight hairs on carpel apices in both species. Plants with columnar caudex branches, representing a significant part of the Alaskan material, have been called subsp. congesta. This morphology results from the persistence of marcescent whole leaves for several years (in typical P. villosula only sheaths and petioles are retained). This character suggests that P. subvahliana, with which the form called subsp. congesta is sympatric, may be part of its parentage. Potentilla villosula is accepted here in a fairly collective sense, possibly including several hybrid lineages, but with P. villosa a part of them all. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
||||
Key |
|
|||||
Source | FNA vol. 9, p. 171. | FNA vol. 9, p. 202. | ||||
Parent taxa | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Multijugae | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Niveae | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | P. diversifolia var. pinnatisecta, P. pinnatisecta, P. plattensis var. pinnatisecta | P. villosula subsp. congesta | ||||
Name authority | J. M. Macoun: Canad. Rec. Sci. 6: 464. (1896) | Jurtzev: in A. I. Tolmatchew, Fl. Arct. URSS 9(1): 319. (1984) | ||||
Web links |