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Labrador buttercup, prairie buttercup, prairie crowfoot

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

Roots

slender, 0.8-1.8 mm thick.

slender or fusiform-thickened basally, glabrous.

Stems

erect, 5-22 cm, pilose or occasionally glabrous, each with 3-12 flowers.

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

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.

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.

Inflorescences

bracts lanceolate.

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 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.

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 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.

2n

= 16.

Ranunculus rhomboideus

Ranunculus alismifolius

Phenology Flowering spring (Apr–Jun).
Habitat Prairies, or occasionally open woods or thickets
Elevation 0-900 m (0-3000 ft)
Distribution
from FNA
IA; IL; MI; MN; MT; ND; NE; SD; WI; AB; BC; MB; NT; ON; SK
[WildflowerSearch map]
[BONAP county map]
from FNA
CA; CO; ID; MT; NV; OR; UT; WA; WY; BC
[WildflowerSearch map]
[BONAP county map]
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.)

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. Epirotes 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. 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. 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. 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
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
Name authority Goldie: Edinburgh J. Sci. 6: 329. (1822) Geyer ex Bentham: Pl. Hartw., 295. (1849)
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