Ranunculus pusillus |
Ranunculus gelidus |
|
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low buttercup, low spearwort, weak buttercup |
arctic buttercup, modest buttercup, wetslope buttercup |
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Roots | not thickened basally, glabrous. |
slender, 0.5-1 mm thick. |
Stems | erect or ascending, rooting at most proximal nodes, glabrous. |
erect or decumbent from short caudices, 3-22 cm, glabrous, each with 1-5 flowers. |
Basal leaves | persistent, blades cordate or reniform, 3-parted, 0.5-1.8 × 0.8-3 cm, segments again lobed, base truncate or nearly cordate, apices of segments rounded. |
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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. |
pedicels pubescent or glabrous; receptacle glabrous or pubescent; sepals 3-5 × 1-4 mm, pubescent or glabrous; petals 5, 3-6 × 1-5 mm; nectary scale glabrous. |
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. |
cylindric to ovoid-cylindric, 4-13 × 4-6 mm; achenes 1.2-2.4 × 0.8-2 mm, glabrous; beak subulate, curved or hooked, 0.4-0.8 mm. |
2n | = 16. |
|
Ranunculus pusillus |
Ranunculus gelidus |
|
Phenology | Flowering spring (Apr–Jun). | Flowering late spring–summer (Jun–Aug). |
Habitat | Ditches, ponds, and swamps | Open arctic and alpine slopes |
Elevation | 0-300 m (0-1000 ft) | 0-4000 m (0-13100 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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AK; CO; ID; MT; OR; UT; WA; WY; AB; BC; NT; YT; Asia
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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.) |
Plants with small achenes are often separated as Ranunculus verecundus. Achene size varies continuously over the range given, however, and it is not correlated with the minor shape difference mentioned by L. D. Benson (1948). (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. Epirotes |
Sibling taxa | ||
Synonyms | R. oblongifolius, R. pusillus var. angustifolius, R. tener | R. gelidus subsp. grayi, R. grayi, R. verecundus |
Name authority | Poiret: in J. Lamarck et al., Encycl. 6: 99. (1804) | Karelin & Kirilov: Bull. Soc. Imp. Naturalistes Moscou 15: 133. (1842) |
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