The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

Labrador buttercup, prairie buttercup, prairie crowfoot

renoncule soufrée, sulphur buttercup

Roots

slender, 0.8-1.8 mm thick.

slender, 0.4-1 mm thick.

Stems

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

erect from short caudices, 3-20 cm, sparsely pilose to glabrous, each with 1-3 flowers.

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.

persistent, blades transversely elliptic to orbiculate, 1-3 × 1-3 cm, base obtuse to nearly truncate, margins crenate or else blades shallowly 3-lobed with crenate lateral lobes, apex rounded or rounded-apiculate.

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.

pedicels sparsely brown-pilose;

receptacle brown-pilose;

sepals 6-8 × 3-6 mm, abaxially densely brown-hispid;

petals 5(-6), 8-12 × 6-10 mm;

nectary scale 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.

ovoid-cylindric or ovoid, 6-7(-9) × 5-6 mm;

achenes 1.8-2.2 × 1.4-1.8 mm, glabrous or sparsely brown-hispid;

beak slender, straight or curved, 0.8-1.4 mm.

2n

= 16.

= 42, ca. 80, ca. 84, 96, ca. 98.

Ranunculus rhomboideus

Ranunculus sulphureus

Phenology Flowering spring (Apr–Jun). Flowering late spring–summer (Jun–Sep).
Habitat Prairies, or occasionally open woods or thickets Meadows and seepy slopes, often around late snowbeds, bogs, and streamsides
Elevation 0-900 m (0-3000 ft) 0-1100 m (0-3600 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
AK; BC; NF; NT; QC; YT; Greenland; Eurasia
[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.)

Material of Ranunculus sulphureus from the Aleutian Islands has 3-lobed leaves similar to those of R. nivalis. These plants are sometimes separated as R. sulphureus var. intercedens.

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

Source FNA vol. 3. FNA vol. 3.
Parent taxa Ranunculaceae > Ranunculus > subg. Ranunculus > sect. Epirotes Ranunculaceae > Ranunculus > subg. Ranunculus > sect. Epirotes
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. 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. rhomboideus, R. sabinei, R. sardous, R. sceleratus, R. testiculatus, R. trilobus, R. triternatus, R. turneri, R. uncinatus
Synonyms R. sulphureus var. intercedens
Name authority Goldie: Edinburgh J. Sci. 6: 329. (1822) Solander: in C. J. Phipps, Voy. North Pole, 202. (1774)
Web links