Ranunculus pusillus |
Ranunculus marginatus |
|
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low buttercup, low spearwort, weak buttercup |
margined buttercup |
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Roots | not thickened basally, glabrous. |
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Stems | erect or ascending, rooting at most proximal nodes, glabrous. |
erect, sparsely pilose. |
Basal leaf | blades reniform to semicircular, undivided or shallowly 3-lobed, 2.5-5 × 3-7 cm, base truncate to nearly cordate, margins crenate or dentate, apex rounded or obtuse. |
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Proximal cauline leaf blades | ovate or lanceolate, 1.2-4.2 × 0.5-1.2 cm, base acute to truncate, margins entire or denticulate, apex acuminate to rounded. |
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Inflorescences | bracts linear to lanceolate or oblanceolate. |
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Flowers | receptacle glabrous; sepals 4-5, spreading or reflexed from base, 1.5-3 × 1-1.5 mm, glabrous or sparsely hirsute; petals 1-3, 1.5-2 × 0.5-1 mm; nectary scales glabrous. |
pedicellate; receptacle hispid; sepals 5, reflexed 1 mm from base, 3-5 × 1-2 mm, hispid; petals 5, 4-5 × 2-3.5 mm. |
Heads of achenes | hemispheric to cylindric, 2-8 × 2-3 mm; achenes 1-1.2 × 0.6-0.8 mm, ± tuberculate, glabrous; beak absent or nearly so, to 0.1 mm. |
hemispheric to globose, 4 × 6 mm; achenes 15-20 per head, 2.5-3 × 2-2.5 mm, faces covered with high sharp tubercles or low spines, glabrous, margin smooth; beak deltate, straight, 0.8-1 mm. |
Ranunculus pusillus |
Ranunculus marginatus |
|
Phenology | Flowering spring (Apr–Jun). | Flowering spring (Mar–May). |
Habitat | Ditches, ponds, and swamps | Roadsides |
Elevation | 0-300 m (0-1000 ft) | 0-100 m (0-300 ft) |
Distribution |
AL; AR; CA; DC; DE; FL; GA; IL; IN; KY; LA; MD; MO; MS; NC; NJ; NY; OH; OK; PA; SC; TN; TX; VA; WV
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AL; LA; TX; native to Europe [Introduced in North America] |
Discussion | In most specimens of Ranunculus pusillus, the heads of achenes are hemispheric to short-ovate and only 2-3 mm. Occasional plants with cylindric heads of achenes 4-6 mm from the Gulf Coast states have been called R. pusillus var. angustifolius. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
A form of Ranunculus marginatus, with the fruits weakly tuberculate or almost smooth, similar to the smooth-fruited forms of R. sardous, is found in Europe; it is not known from North America. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 3. | FNA vol. 3. |
Parent taxa | Ranunculaceae > Ranunculus > subg. Ranunculus > sect. Flammula | Ranunculaceae > Ranunculus > subg. Ranunculus > sect. Echinella |
Sibling taxa | ||
Synonyms | R. oblongifolius, R. pusillus var. angustifolius, R. tener | |
Name authority | Poiret: in J. Lamarck et al., Encycl. 6: 99. (1804) | d'Urville: Mém. Soc. Linn. Paris 1: 318. (1822) |
Web links |