Ranunculus rhomboideus |
Ranunculus pusillus |
|
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Labrador buttercup, prairie buttercup, prairie crowfoot |
low buttercup, low spearwort, weak buttercup |
|
Roots | slender, 0.8-1.8 mm thick. |
not thickened basally, glabrous. |
Stems | erect, 5-22 cm, pilose or occasionally glabrous, each with 3-12 flowers. |
erect or ascending, rooting at most proximal nodes, glabrous. |
Basal leaves | persistent, blades ovate to rhombic, undivided or rarely innermost 3-parted, 1.1-5.3 × 0.9-3.6 cm, base obtuse, margins crenate with 5 crenae, apex rounded. |
|
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. |
|
Inflorescences | bracts linear to lanceolate or oblanceolate. |
|
Flowers | pedicels pilose; receptacle pilose; sepals 4-6 × 1.5-3 mm, abaxially pilose, hairs colorless; petals 5, 6-8 × 2-4 mm; nectary scale glabrous. |
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. |
Heads of achenes | depressed-globose, 4-6 × 5-7 mm; achenes 1.8-2.2 × 1.2-1.8 mm, glabrous; beak slender, curved, 0.2-0.3 mm. |
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. |
2n | = 16. |
|
Ranunculus rhomboideus |
Ranunculus pusillus |
|
Phenology | Flowering spring (Apr–Jun). | Flowering spring (Apr–Jun). |
Habitat | Prairies, or occasionally open woods or thickets | Ditches, ponds, and swamps |
Elevation | 0-900 m (0-3000 ft) | 0-300 m (0-1000 ft) |
Distribution |
IA; IL; MI; MN; MT; ND; NE; SD; WI; AB; BC; MB; NT; ON; SK
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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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Discussion | In addition to the range given above, L. D. Benson (1948) cited nineteenth-century specimens from Quebec, New York, Massachusetts, and Rhode Island. No modern specimens have been seen from those areas. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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.) |
Source | FNA vol. 3. | FNA vol. 3. |
Parent taxa | Ranunculaceae > Ranunculus > subg. Ranunculus > sect. Epirotes | Ranunculaceae > Ranunculus > subg. Ranunculus > sect. Flammula |
Sibling taxa | ||
Synonyms | R. oblongifolius, R. pusillus var. angustifolius, R. tener | |
Name authority | Goldie: Edinburgh J. Sci. 6: 329. (1822) | Poiret: in J. Lamarck et al., Encycl. 6: 99. (1804) |
Web links |