Ranunculus arvensis |
Ranunculus pusillus |
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corn buttercup, devil-on-all-sides, field buttercup, hungerweed |
low buttercup, low spearwort, weak buttercup |
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Roots | not thickened basally, glabrous. |
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Stems | erect or ascending, sparsely pilose. |
erect or ascending, rooting at most proximal nodes, glabrous. |
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 | pedicellate; receptacle sparsely hispid; sepals 5, spreading, 4-7 × 1-2 mm, strigose; petals 5, 5-8 × 2-4 mm. |
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 | discoid, 8-9 mm across; achenes 5-8 per head, 4-6.4 × 2.8-4.4 mm, faces and margin covered with long spines, glabrous; beak lance-subulate, straight, 1.6-3.8 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. |
Basal | and lower cauline leaf blades obovate to rhombic in outline, 3-parted or 3(-5)-foliolate, 1.8-5.2 × 1.6-4.2 cm, leaflets oblanceolate or divided into oblanceolate or linear segments, leaflet base narrowly acuminate, margins entire or distally dentate, apex rounded or acuminate. |
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Ranunculus arvensis |
Ranunculus pusillus |
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Phenology | Flowering spring (Mar–Jun). | Flowering spring (Apr–Jun). |
Habitat | Grasslands, ephemeral pools, disturbed areas | Ditches, ponds, and swamps |
Elevation | 0-1200 m (0-3900 ft) | 0-300 m (0-1000 ft) |
Distribution |
AR; CA; DC; GA; ID; IL; KS; LA; MO; MS; NC; NJ; NY; OR; PA; SC; TN; UT; WA; South America; native to Eurasia; Pacific Islands; Australia [Introduced in North America]
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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 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.) |
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Source | FNA vol. 3. | FNA vol. 3. |
Parent taxa | Ranunculaceae > Ranunculus > subg. Ranunculus > sect. Echinella | Ranunculaceae > Ranunculus > subg. Ranunculus > sect. Flammula |
Sibling taxa | ||
Synonyms | R. arvensis var. tuberculatus | R. oblongifolius, R. pusillus var. angustifolius, R. tener |
Name authority | Linnaeus: Sp. Pl. 1: 555. (1753) | Poiret: in J. Lamarck et al., Encycl. 6: 99. (1804) |
Web links |
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