Potentilla anglica |
Potentilla lasiodonta |
|
---|---|---|
English cinquefoil, potentille d'angleterre, trailing cinquefoil, trailing tormentil, wood cinquefoil |
Sandhills cinquefoil |
|
Stems | soon becoming prostrate, ± flagelliform, usually openly branched, eventually rooting at some nodes, (0.3–)1.5–7+ dm. |
± erect, 2–4 dm. |
Basal leaves | ± persistent, ternate or palmate, 2–10(–12) cm; petiole 1–7(–8) cm, long hairs sparse to abundant, appressed, 0.5–1 mm, stiff, glands absent; leaflets 3–5, central ± obovate to cuneate, 1–3(–3.5) × 0.8–2(–2.5) cm, distal ± 1/2 of margin incised 1/4–1/3(–1/2) to midvein, teeth 2–4 per side, surfaces similar, green, sparsely to moderately hairy. |
pinnate, 12–20(–30) cm; petiole 5–10(–15) cm, long hairs ± abundant, spreading to ascending, 0.5–1 mm, weak to ± stiff, short hairs abundant to dense, cottony or crisped hairs absent, glands sparse to abundant, often obscured; leaflets 4–6(–9) per side, on distal (1/3–)1/2–3/5 of leaf axis, slightly overlapping, terminal ones oblanceolate to narrowly elliptic, 3–6 × 0.8–1.2(–1.5) cm, margins strongly revolute, incised ± 1/2 to midvein, undivided medial blade 5–9 mm wide, teeth 8–12 per side, narrowly triangular to lanceolate, surfaces ± dissimilar, abaxial grayish, long hairs ± sparse (or not differentiated from short hairs), 0.5–1.5 mm, weak, short hairs abundant to dense, cottony or crisped hairs absent, glands sparse or obscured, adaxial ± green, straight hairs (long and short not differentiated) abundant, spreading to ascending, 0.2–0.5 mm, cottony and crisped hairs absent, glands sparse to abundant, often obscured. |
Cauline leaves | 2–3(–4) proximal to 1st flowering or branching node, usually well expanded at anthesis, usually ternate, 2–6(–10) cm; petiole 0.3–4(–8) cm; leaflets (3–)5, ± resembling or narrower than those of basal leaves, narrowly cuneate, 1–2(–3.5) × 0.8–2(–2.5) cm, apex rounded to obtuse. |
(1–)2–4. |
Inflorescences | solitary flowers at stolon nodes. |
10–40-flowered, congested or elongating in fruit. |
Pedicels | (1–)3–10(–17) cm. |
± 0.1 cm (proximal to 1.2 cm). |
Flowers | 4(–5)-merous; epicalyx bractlets narrowly elliptic to oblong or ovate, 3–4(–7) × 1–1.5 mm, smaller than to slightly larger than sepals; hypanthium 2–4 mm diam.; sepals (3–)4–6 mm, apex broadly acute or acuminate; petals 6–9 × 5–9 mm, apex ± retuse; stamens 15–20, filaments 0.8–1.2 mm, anthers 0.8–1.2 mm; carpels 20–50, styles 0.9–1.5 mm. |
epicalyx bractlets narrowly ovate-acuminate, (3–)4–8(–10) × 2–3 mm, lengths 1–2 times sepals, margins ± revolute; hypanthium (4–)5–10 mm diam.; sepals 3–5 mm, apex acute to obtuse, abaxial surfaces: venation moderate, glands ± abundant, obscured to evident; petals pale yellow, 3–5 × 2–4 mm, lengths ± equal to or shorter than sepals; filaments 1–1.5 mm, anthers 0.5–0.8 mm; carpels 80–90, styles papillate-swollen in proximal 3/4+, 1–1.2 mm. |
Achenes | 1–1.5(–1.8) mm, ± smooth. |
± 1 mm, ± rugose. |
Rootstocks | ± erect, stout to slender, 1–4 cm. |
|
2n | = 28, 56 (Europe). |
= 14. |
Potentilla anglica |
Potentilla lasiodonta |
|
Phenology | Flowering May–Aug(–Nov). | Flowering summer. |
Habitat | Moist flats and slopes, mainly on acidic soil | Sandy sites in prairies |
Elevation | 0–1200 m (0–3900 ft) | 300–1100 m (1000–3600 ft) |
Distribution |
CA; CO; ME; NY; OR; PA; UT; WA; BC; NL; NS; QC; SPM; Europe [Introduced in North America; introduced also in Atlantic Islands (Azores, Madeira), Pacific Islands (New Zealand), Australia]
|
MN; ND; AB; MB; SK |
Discussion | Potentilla anglica apparently is a product of hybridization involving P. erecta and P. reptans (B. Matfield and J. R. Ellis 1972) that has become stabilized and distinct from both parents. In Europe, it forms back-cross hybrids with both P. erecta (P. ×suberecta Zimmeter) and P. reptans (P. ×mixta Nolte); these hybrids are not known from North America. A garden hybrid supposedly between P. anglica and P. nepalensis Hooker (known as P. ×tonguei Mallett) was found in Allegany State Park, New York, but this was likely cultivated rather than naturalized. Potentilla anglica probably was introduced even in Newfoundland (A. Kurtto et al. in J. Jalas et al. 1972+, vol. 13), contrary to the view expressed by M. L. Fernald (1950). The name Potentilla procumbens Sibthorp was previously used for this species; that is a superfluous and illegitimate name. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Potentilla lasiodonta is a diploid relative of tetraploid P. pensylvanica, sharing similar velvety vestiture of dense short hairs, pinnate leaves, and epicalyx bractlets with revolute margins. The species differs in having larger epicalyx bractlets and less deeply incised leaflets. Plant height and leaf size are at the upper range of P. pensylvanica, and populations are evidently restricted to sandy substrates. Occurrence in Manitoba is based on B. L. Kohli and J. G. Packer (1976); no vouchers are in WIN. At least one collection from southeastern British Columbia (Brown 779, MO) approaches P. lasiodonta, but it is insufficient by itself to serve as a provincial record. The fundamental ploidy and epicalyx distinctions of this species were established by B. L. Kohli and J. G. Packer (1976), who proposed the name Potentilla finitima. As noted by J. Soják (1994), the type of P. lasiodonta is the same entity. Potentilla atrovirens Rydberg and P. pensylvanica var. arida B. Boivin have sometimes been applied to this taxon; the types of both names fall within the circumscription of P. pensylvanica in the narrow sense (Packer, pers. comm.). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 9, p. 135. | FNA vol. 9, p. 214. |
Parent taxa | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Potentilla | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Pensylvanicae |
Sibling taxa | ||
Synonyms | P. finitima | |
Name authority | Laicharding: Veg. Europ. 1: 475. (1790) | Rydberg: in N. L. Britton et al., N. Amer. Fl. 22: 351. (1908) |
Web links |
|