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Cusick's buttercup, mountain buttercup, popular buttercup

dwarf buttercup, pygmy buttercup

Roots

thickened basally, glabrous.

slender, 0.1-0.6 mm thick.

Stems

erect or ascending, never rooting nodally, glabrous.

erect or ascending from short caudices, 0.6-3.5 cm (sometimes longer in fruit), each with 1-2 flowers.

Leaves

basal leaf blades with base obtuse to cordate;

proximal cauline leaf blades semicircular to cordate or ovate, 1.2-5.1 × 1.5-2.9 cm, base cordate to broadly obtuse, margins entire or crenulate, apex broadly acute to rounded.

Basal leaves

persistent, blades reniform to transversely elliptic or semicircular, 3-parted or -divided, 0.45-0.9 × 0.6-1.3 cm, at least lateral segments again lobed, base truncate or nearly cordate, margins entire, apex rounded to obtuse.

Inflorescences

bracts narrowly elliptic to ovate or lanceolate.

Flowers

receptacle glabrous or hispidulous;

sepals 4-5, spreading or reflexed from base, 3-5 × 2-4 mm, glabrous;

petals 5-6, 4-9 × 2-5 mm;

nectary scales glabrous.

pedicels glabrous or pubescent;

receptacle glabrous;

sepals 2-4 × 1.2-1.6 mm, abaxially sparsely hairy, hairs colorless;

petals 5, 1.2-3.5 × 1.1-2.8 mm;

nectary scale glabrous.

Heads of achenes

hemispheric, 3 × 4-5 mm;

achenes 1.6-1.8 × 1.2 mm, glabrous;

beak lance-subulate, straight, 0.2-1 mm.

nearly globose to cylindric, 2.5-7 × 2.5-5 mm;

achenes 1-1.2 × 0.8-1.1 mm, glabrous;

beak subulate, straight or curved, 0.3-0.7 mm.

2n

= 16.

Ranunculus populago

Ranunculus pygmaeus

Phenology Flowering spring–summer (Apr–Aug). Flowering summer (Jul–Sep).
Habitat Wet ground and shallow water, in wet meadows, bogs, streams, lakes Arctic and alpine meadows and slopes, usually around persistent snow patches
Elevation 1300-2000 m (4300-6600 ft) 0-4000 m (0-13100 ft)
Distribution
from FNA
CA; ID; MT; OR; WA
[WildflowerSearch map]
[BONAP county map]
from FNA
AK; CO; ID; MT; UT; WY; AB; BC; NF; NT; QC; YT; Greenland; Europe (Spitsbergen)
[WildflowerSearch map]
[BONAP county map]
Discussion

Ranunculus pygmaeus var. langeana has been described as having deeply divided basal leaves and strongly elongate heads of achenes (at least 5 mm). These characteristics are not well correlated with one another, however, and the variety does not seem natural.

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

Source FNA vol. 3. FNA vol. 3.
Parent taxa Ranunculaceae > Ranunculus > subg. Ranunculus > sect. Flammula 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. 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. pusillus, 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. pygmaeus var. langeana
Name authority Greene: Erythea 3: 19. (1895) Wahlenberg: Fl. Lapp., 157. (1812)
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