Ranunculus bonariensis
Ranunculus orthorhynchus
Carter's buttercup
Bloomer's buttercup, straight-beak buttercup, swamp buttercup
sometimes fleshy and ± tuberous.
nearly erect or decumbent, never rooting nodally, hispid, strigose, or glabrous, base not bulbous.
narrowly ovate to oblong or semicircular in outline, simple to 3-5-lobed or -foliolate, 2.8-12.5 × 2.5-14 cm, leaflets or segments undivided or 1-2x-lobed or -parted, ultimate segments circular to linear, margins dentate, crenate, or entire, apex rounded to narrowly acute.
receptacle hispid;
sepals reflexed 1-2 mm above base, 5-11 × 2-4 mm, hispid, hirsute, or glabrous;
petals 5-6, abaxially yellow or red, adaxially yellow, 8-18 × 4-11 mm.
hemispheric to ovoid, 5-13 × 6-10 mm;
achenes 2.8-4.5 × 1.8-3.2 mm, glabrous, margin forming narrow rib 0.1-0.2 mm wide;
beak persistent, narrowly lanceolate to subulate, straight, 1.8-3.8(-4.8) mm.
Ranunculus bonariensis
Ranunculus orthorhynchus
Varieties 3 (1 in the flora).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Varieties 3
The first two varieties (Ranunculus orthorhynchus var. orthorhynchus and R. orthorhynchus var. platyphyllus) are rather weak, intergrading extensively in California and Oregon. By contrast, R. orthorhynchus var. bloomeri often grows with the others with little or no intergradation (although intermediate populations are found in some areas), and it has been treated as a distinct species, R. bloomeri, by many taxonomists.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Basal leaves simple or 3-foliolate, if compound then leaflets undivided, margins crenate; petals retuse. | var. bloomeri |
1. Basal leaves 3–5-foliolate, leaflets lobed or parted, margins entire or dentate; petals truncate or rounded. | → 2 |
2. Heads of achenes hemispheric or sometimes globose, 5–7 mm; petals often abaxially red. | var. orthorhynchus |
2. Heads of achenes globose or ovoid, 8–13 mm; petals yellow. | var. platyphyllus |
- 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
