Ranunculus glaberrimus
Ranunculus acris
sagebrush buttercup, smooth buttercup
acrid buttercup, bouton d'or, meadow buttercup, renoncule âcre, tall buttercup, tall crowfoot
cylindric, 1-3 mm thick.
never tuberous.
prostrate or ascending, 4-15 cm, glabrous, each with 1-4 flowers.
erect from short caudex or rhizome, never rooting nodally, hispid, strigose, or glabrous, base not bulbous.
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.
pentagonal in outline, deeply 3-5-parted, 1.8-5.2 × 2.7-9.8 cm, segments 1-2x-lobed or -parted, ultimate segments narrowly elliptic or oblong to lanceolate, margins toothed or lobulate, apex acute to rounded.
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.
receptacle glabrous;
sepals spreading, 4-6(-9) × 2-5 mm, hispid;
petals 5, yellow, 8-11(-17) × 7-13 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.
globose, 5-7(-10) mm wide;
achenes 2-3 × 1.8-2.4 mm, glabrous, margin forming narrow rib 0.1-0.2 mm wide;
beak persistent, deltate, usually with tip short or long, straight or curved, subulate, 0.2-1 mm.
= 14.
Ranunculus glaberrimus
Ranunculus acris
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.)
Ranunculus acris is variable in form and division of leaves, size of achene beak, and form of indument on the proximal stem. Most North American plants are weedy and have poorly differentiated caudices; these forms probably were introduced from Eurasia. Rhizomatous plants with large flowers (parenthetic measurements above) found in the Aleutian Islands of Alaska and in Greenland are probably native. Aleutian populations of this form have been called R. acris var. frigidus Regel or R. grandis Honda var. austrokurilensis (Tatewaki) H. Hara. Both names were originally applied to Asiatic plants, and their applicability to American specimens is open to question.
Some Native American tribes used Ranunculus acris as an analgesic, a dermatological or oral aid, an antidiarrheal, antihermorrhagic, and a sedative (D. E. Moerman 1986).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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 |
- 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
- Local floras: BC, CA, OR, WA
- Local Web sites: CalFlora, CalPhotos, Flora NW,
Go Botany, 
IL Wildflowers, 
KS Wildflowers, 
MD Biodiversity, 
MI Flora, 
MN Wildflowers, 
MO Plants, PNW Herbaria - WildflowerSearch
- iNaturalist (observations)
- USDA Plants Database
- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
