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western buttercup

sagebrush buttercup, smooth buttercup

Roots

never tuberous.

cylindric, 1-3 mm thick.

Stems

erect to reclining, not rooting nodally, hirsute or sometimes pilose or glabrous, base not bulbous.

prostrate or ascending, 4-15 cm, glabrous, each with 1-4 flowers.

Basal leaves

persistent, blades reniform or obovate to very narrowly elliptic, 0.7-5.2 × 1-2 cm, base truncate, obtuse or attenuate, margins entire or with 3 broad, apical crenae, apex rounded to acute.

Basal leaf blades

broadly ovate to semicircular or reniform in outline, 3-parted or -foliolate, 1.5-5.3 × 2.2-8 cm, segments usually again 1(-2)×-lobed, ultimate segments oblong or elliptic to lanceolate or oblanceolate, margins dentate (sometimes dentate-lobulate or entire), apex acute to rounded-obtuse.

Flowers

receptacle glabrous;

sepals reflexed 2-3 mm above base, 4-7(-9) × 2-4 mm, hirsute;

petals 5-14, yellow, 5-13 × 1.5-8 mm.

pedicels glabrous or nearly so;

receptacle glabrous;

sepals 5-8 × 3-7 mm, abaxially glabrous or sparsely pilose, hairs colorless;

petals 5-10, 8-13 × 5-12 mm;

nectary scale glabrous or ciliate.

Heads of achenes

hemispheric, 3-7 × 5-9 mm;

achenes 2.6-3.6(-4.8) × 1.8-3(-3.2) mm, glabrous, rarely hispid, margin forming narrow rib 0.1-0.2 mm wide;

beak persistent, lanceolate to lance-subulate, straight or curved, 0.4-2.2 mm.

globose, 7-12(-20) × 6-11(-20) mm;

achenes 1.4-2.2 × 1.1-1.8 mm, usually finely pubescent;

beak subulate or lance-subulate, straight or curved, 0.4-1 mm.

Ranunculus occidentalis

Ranunculus glaberrimus

Distribution
from FNA
AK; CA; NV; OR; WA; AB; BC; YT
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ; CA; CO; ID; MT; ND; NE; NM; NV; OR; SD; UT; WA; WY; AB; BC; SK
[WildflowerSearch map]
[BONAP county map]
Discussion

Varieties 7

The seeds of Ranunculus occidentalis were eaten by some Californian Indians. D. E. Moerman (1986) identified this taxon as an Aleut poison: juice of the flowers could be slipped into food to poison the person who ate it.

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

Varieties 2 (2 in the flora).

Usually only a minority of the ovaries develop, and the fruiting receptacle is completely hidden by aborted ovaries. Populations growing at high elevations (Ranunculus glaberrimus var. ellipticus) and low elevations (var. glaberrimus) are usually well differentiated, but these varieties intergrade at intermediate elevations.

The Thompson Indians rubbed the flowers or the whole plant of Ranunculus glaberrimus on arrow points as a poison (D. E. Moerman 1986).

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

Key
1. Petals 8-14; Queen Charlotte Islands, B.C.
var. hexasepalus
1. Petals 5-6; widespread.
→ 2
2. Stem 4-8 mm thick; beak of achene 1.8-2.4 mm, curved; coastal Alaska.
var. nelsonii
2. Stem 1-3(-4) mm thick; beak of achene either 0.4-1.4 mm and curved, or 1.2-2.2 mm and straight; widespread.
→ 3
3. Beak of achene straight, 1.2-2.2 mm; Oregon and northernmost California.
→ 4
3. Beak of achene curved, 0.4-1.4 mm; widespread.
→ 5
4. Ultimate segments of leaves lanceolate to oblanceolate.
var. dissectus
4. Ultimate segments of leaves elliptic.
var. howellii
5. Petals 1.5-2.5 mm wide; beak of achene 0.4-1.2 mm; stems ± reclining; Sierra Nevada, above 1000m.
var. ultramontanus
5. Petals 3-8 mm wide; beak of achene (0.6-)1-1.4 mm; stems erect or reclining; widespread.
→ 6
6. Stems pilose or glabrous; Alaska to c British Columbia and Alberta.
var. brevistylis
6. Stems hirsute, sometimes glabrous; California to sw British Columbia.
var. occidentalis
1. Basal leaf blades ovate to obovate, usually shallowly lobed; bracts 3-lobed, lobes equal in size; 400–2000 m.
var. glaberrimus
1. Basal leaf blades elliptic to oblanceolate, usually undivided; bracts 3-lobed, middle lobe much larger; 1200–3600 m.
var. ellipticus
Source FNA vol. 3. FNA vol. 3.
Parent taxa Ranunculaceae > Ranunculus > subg. Ranunculus > sect. Ranunculus 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. 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. 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. occidentalis var. brevistylis, R. occidentalis var. dissectus, R. occidentalis var. hexasepalus, R. occidentalis var. howellii, R. occidentalis var. nelsonii, R. occidentalis var. occidentalis, R. occidentalis var. ultramontanus
R. glaberrimus var. ellipticus, R. glaberrimus var. glaberrimus
Name authority Nuttall: in J. Torrey & A. Gray, Fl. N. Amer. 1: 22. (1838) Hooker: Fl. Bor.-Amer. 1: 12. (1829)
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