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corn buttercup, devil-on-all-sides, field buttercup, hungerweed

low buttercup, low spearwort, weak buttercup

Roots

not thickened basally, glabrous.

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.

Inflorescences

bracts linear to lanceolate or oblanceolate.

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.

Ranunculus arvensis

Ranunculus pusillus

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
from FNA
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]
[WildflowerSearch map]
[BONAP county map]
from FNA
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
[WildflowerSearch map]
[BONAP county map]
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.)

Source FNA vol. 3. FNA vol. 3.
Parent taxa Ranunculaceae > Ranunculus > subg. Ranunculus > sect. Echinella Ranunculaceae > Ranunculus > subg. Ranunculus > sect. Flammula
Sibling taxa
R. abortivus, R. acriformis, R. acris, R. adoneus, R. alismifolius, R. allegheniensis, R. allenii, R. ambigens, R. andersonii, R. aquatilis, R. arizonicus, R. auricomus, R. austro-oreganus, R. bonariensis, R. bulbosus, R. californicus, R. canus, R. cardiophyllus, R. cooleyae, R. cymbalaria, R. eschscholtzii, R. fascicularis, R. fasciculatus, R. ficaria, R. flabellaris, R. flammula, R. gelidus, R. glaberrimus, R. glacialis, R. gmelinii, R. gormanii, R. harveyi, R. hebecarpus, R. hederaceus, R. hispidus, R. hydrocharoides, R. hyperboreus, R. hystriculus, R. inamoenus, R. jovis, R. kamtschaticus, R. lapponicus, R. laxicaulis, R. lobbii, R. macauleyi, R. macounii, R. macranthus, R. marginatus, R. micranthus, R. muricatus, R. nivalis, R. occidentalis, R. oresterus, R. orthorhynchus, R. pacificus, R. pallasii, R. parviflorus, R. pedatifidus, R. pensylvanicus, R. platensis, R. populago, R. pusillus, R. pygmaeus, R. ranunculinus, R. recurvatus, R. repens, R. rhomboideus, R. sabinei, R. sardous, R. sceleratus, R. sulphureus, R. testiculatus, R. trilobus, R. triternatus, R. turneri, R. uncinatus
R. abortivus, R. acriformis, R. acris, R. adoneus, R. alismifolius, R. allegheniensis, R. allenii, R. ambigens, R. andersonii, R. aquatilis, R. arizonicus, R. arvensis, R. auricomus, R. austro-oreganus, R. bonariensis, R. bulbosus, R. californicus, R. canus, R. cardiophyllus, R. cooleyae, R. cymbalaria, R. eschscholtzii, R. fascicularis, R. fasciculatus, R. ficaria, R. flabellaris, R. flammula, R. gelidus, R. glaberrimus, R. glacialis, R. gmelinii, R. gormanii, R. harveyi, R. hebecarpus, R. hederaceus, R. hispidus, R. hydrocharoides, R. hyperboreus, R. hystriculus, R. inamoenus, R. jovis, R. kamtschaticus, R. lapponicus, R. laxicaulis, R. lobbii, R. macauleyi, R. macounii, R. macranthus, R. marginatus, R. micranthus, R. muricatus, R. nivalis, R. occidentalis, R. oresterus, R. orthorhynchus, R. pacificus, R. pallasii, R. parviflorus, R. pedatifidus, R. pensylvanicus, R. platensis, R. populago, R. pygmaeus, R. ranunculinus, R. recurvatus, R. repens, R. rhomboideus, R. sabinei, R. sardous, R. sceleratus, R. sulphureus, R. testiculatus, R. trilobus, R. triternatus, R. turneri, R. uncinatus
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)
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