Ranunculus adoneus
Ranunculus occidentalis
alpine buttercup
western buttercup
slender, 0.8-1.4 mm thick.
never tuberous.
erect from large caudices, 9-25 cm, glabrous, each with 1-3 flowers.
erect to reclining, not rooting nodally, hirsute or sometimes pilose or glabrous, base not bulbous.
persistent, blades circular to reniform in outline, 2-3x-dissected into linear segments, 0.9-2.5 × 1.1-2.8 cm, base obtuse, margins entire, apices of segments narrowly rounded to acute.
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.
pedicels glabrous;
receptacle glabrous;
sepals 4-11 × 3-7 mm, abaxially sparsely pilose, hairs colorless;
petals 5-10, 8-15 × 8-19 mm;
nectary scale glabrous.
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.
ovoid, 6-12 × 5-9 mm;
achenes 1.8-2.4 × 1-1.4 mm, glabrous or nearly so;
beak subulate, straight, 1.2-1.7 mm.
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.
n = 16.
Ranunculus adoneus
Ranunculus occidentalis
Most collections of Ranunculus adoneus from Colorado, including the type specimen, tend to be small, with narrow leaf segments (only 0.5-1 mm wide) and large flowers. The more widespread form, with leaf segments 1-2 mm wide and more variable flowers, has been called R. adoneus var. alpinus. The leaf and flower characteristics are very poorly correlated, however, and specimens referable to var. alpinus vary greatly in stature and flower size, so the two forms scarcely merit formal recognition.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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.)
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 |
- Local floras:
BC, 
CA, 
OR, 
WA - Local Web sites: CalFlora, CalPhotos,
Flora NW, 
PNW Herbaria, Turner Photog. 
WildflowerSearch
iNaturalist (observations)
USDA Plants Database- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
