Potentilla canadensis |
Potentilla uliginosa |
|
---|---|---|
dwarf cinquefoil |
Cunningham Marsh cinquefoil |
|
Habit | Plants rosetted to tufted; taproots not fleshy-thickened. | |
Stems | initially ascending to erect, soon becoming prostrate, flagelliform, not branched, eventually rooting at some nodes, (0.3–)0.5–12 dm. |
probably prostrate to decumbent, or ± ascending in supporting vegetation, 2.5–5.5 dm, lengths 1–2 times basal leaves. |
Basal leaves | ± persistent, usually palmate, 2–9(–11) cm; petiole 1–7(–8) cm, long hairs abundant to dense, appressed to spreading, 1.5–3 mm, mostly ± weak, glands absent or sparse; leaflets (3–)5(–7), central mostly ± obovate to cuneate, sometimes narrowly so, (0.5–)1–4(–6) × (0.5–)0.8–2(–3) cm, distal 1/2 of margin incised 1/4–1/3 to midvein, teeth 2–7 per side, surfaces similar to ± dissimilar, abaxial green to silvery white, sparsely to densely hairy, adaxial green, sparsely to moderately hairy. |
pinnate with distal leaflets ± confluent, 15–32 × 2–4 cm; petiole 5–10(–15) cm, straight hairs absent or sparse to common, appressed, 0.5–1.5 mm, stiff, cottony hairs absent, glands absent or sparse; primary lateral leaflets 6–10(–12) per side (irregularly paired), on distal ± 1/2 of leaf axis, loosely overlapping to proximally separate, largest ones cuneate to flabellate, 1.2–2.2 × 1–3 cm, ± whole margin unevenly incised 3/4 to nearly to midvein, ultimate segments (3–)5–10(–15), linear to narrowly oblanceolate, 5–17 × 1–2.5 mm, apical tufts less than 0.5 mm, surfaces green, not glaucous, straight hairs sparse (often glabrate adaxially), appressed, 0.5–1(–1.5) mm, stiff, cottony hairs absent, glands absent or sparse. |
Cauline leaves | 0–1 proximal to 1st flowering node, not fully expanded at anthesis, usually palmate, 2–7(–9) cm; petiole (0.5–)1–6(–7.5) cm; leaflets (3–)5, ± resembling those of basal leaves, apex rounded to obtuse. |
2. |
Inflorescences | solitary flowers at stolon nodes. |
6–10-flowered, very openly cymose. |
Pedicels | (1–)2–5(–9) cm. |
1–6 cm, ± recurved in fruit. |
Flowers | 5-merous; epicalyx bractlets linear to lanceolate-elliptic, (2–)3–5(–6) × 0.8–1.5 mm, slightly smaller than to ± equal to sepals; hypanthium 2.5–5 mm diam.; sepals (2–)3–5(–6) mm, apex acute; petals 4–6(–8) × 3.5–6.5(–8) mm, apex rounded to slightly retuse; stamens ca. 20, filaments 0.5–2 mm, anthers 0.4–1 mm; carpels 20–40, styles 0.8–1.4 mm. |
epicalyx bractlets narrowly elliptic to oblong-ovate, 4–6 × 1–2.5 mm; hypanthium 5–6 mm diam.; sepals 4–7 mm, apex acute; petals 6–10 × 5–8 mm; filaments (1.5–)2–3 mm, anthers 0.7–1.2 mm; carpels ca. 10, styles 2.5–3.5 mm. |
Achenes | 1.2–1.4 mm, smooth. |
2–2.6 mm, smooth, ± carunculate. |
Rootstocks | erect, stout, 0.5–2 cm. |
|
2n | = 28. |
|
Potentilla canadensis |
Potentilla uliginosa |
|
Phenology | Flowering late Mar–early Jun. | Flowering spring–summer. |
Habitat | Dry flats and slopes in lawns, pastures, roadsides, cherty slopes, dry meadows, edges of oak and conifer woodlands, often on acidic soil | Permanent oligotrophic wetlands |
Elevation | 0–1500 m (0–4900 ft) | 30–40 m (100–100 ft) |
Distribution |
CT; DC; DE; KY; MA; MD; ME; MO; NC; NH; NJ; NY; OH; PA; RI; SC; TN; VA; VT; WV; NS; ON
|
CA |
Discussion | A cream-colored form (ochroleuca) was described from a now-obliterated site in Massachusetts (M. L. Fernald 1931). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. Potentilla uliginosa is known only from a handful of historical collections from Cunningham Marsh, one of three wetlands in southern Sonoma County that harbor a suite of disjunct and regionally rare species (B. C. Johnston and B. Ertter 2010). Although previously included in P. hickmanii, P. uliginosa differs in having woodier caudices, longer stems and leaves, and more deeply incised leaflets occupying less of the leaf axis. Potentilla uliginosa is presumed extinct; however, a morphologically comparable collection of the P. millefolia complex from Josephine County, Oregon (Deer Creek, near Selma, 14 June 1929, Applegate 5735, UC), opens the possibility of additional undiscovered populations in the mountains of northwestern California. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 9, p. 134. | FNA vol. 9, p. 175. |
Parent taxa | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Potentilla | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Potentilla > sect. Multijugae |
Sibling taxa | ||
Synonyms | P. canadensis var. pumila, P. canadensis var. villosissima, P. caroliniana, P. pumila | |
Name authority | Linnaeus: Sp. Pl. 1: 498. (1753) | B. C. Johnston & Ertter: J. Bot. Res. Inst. Texas 4: 14, fig. 1. (2010) |
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