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common water plantain buttercup, kidney-leaf buttercup, plantain-leaf buttercup, water-plantain buttercup

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

Roots

slender or fusiform-thickened basally, glabrous.

Stems

erect or ascending, not rooting nodally, glabrous or hirsute.

erect or ascending, sparsely pilose.

Leaves

basal leaf blades with base acute;

proximal cauline leaf blades lanceolate, ovate, or elliptic, 1.8-14.1 × 0.7-2.9 cm, base acuminate to rounded, margins entire or serrulate, apex obtuse to acuminate.

Inflorescences

bracts lanceolate.

Flowers

receptacle glabrous;

sepals 5, spreading or reflexed from base, 2-6 × 1-4 mm, glabrous or hirsute;

petals 5-12, 5-14 × 2-8 mm;

nectary scales glabrous.

pedicellate;

receptacle sparsely hispid;

sepals 5, spreading, 4-7 × 1-2 mm, strigose;

petals 5, 5-8 × 2-4 mm.

Heads of achenes

hemispheric to globose, 3-7 × 4-8 mm;

achenes 1.6-2.8 × 1.2-2 mm, glabrous or rarely hispid;

beak lance-subulate, straight or weakly curved, 0.4-1.2 mm.

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.

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 alismifolius

Ranunculus arvensis

Phenology Flowering spring (Mar–Jun).
Habitat Grasslands, ephemeral pools, disturbed areas
Elevation 0-1200 m (0-3900 ft)
Distribution
from FNA
CA; CO; ID; MT; NV; OR; UT; WA; WY; BC
[WildflowerSearch map]
[BONAP county map]
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]
Discussion

Varieties 6 (6 in the flora).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Key
1. Petals 7–12 on most flowers, 2–3 mm broad.
var. montanus
1. Petals 4–6(–8), 2–8 mm broad.
→ 2
2. Stems 3.5–8 mm thick; leaf margins serrulate.
var. alismifolius
2. Stems 1–3 mm thick; leaf margins entire.
→ 3
3. Leaf blades ovate or elliptic.
var. alismellus
3. Leaf blades broadly to narrowly lanceolate.
→ 4
4. Petals 10–14 mm; California and Nevada.
var. lemmonii
4. Petals 5–8 mm; widespread.
→ 5
5. Roots fusiform-thickened proximally; stems and petioles glabrous or pubescent.
var. davisii
5. Roots not or scarcely fusiform-thickened proximally; stems and petioles glabrous.
var. hartwegii
Source FNA vol. 3. FNA vol. 3.
Parent taxa Ranunculaceae > Ranunculus > subg. Ranunculus > sect. Flammula Ranunculaceae > Ranunculus > subg. Ranunculus > sect. Echinella
Sibling taxa
R. abortivus, R. acriformis, R. acris, R. adoneus, 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. 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. 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
Subordinate taxa
R. alismifolius var. alismellus, R. alismifolius var. alismifolius, R. alismifolius var. davisii, R. alismifolius var. hartwegii, R. alismifolius var. lemmonii, R. alismifolius var. montanus
Synonyms R. arvensis var. tuberculatus
Name authority Geyer ex Bentham: Pl. Hartw., 295. (1849) Linnaeus: Sp. Pl. 1: 555. (1753)
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