Ranunculus orthorhynchus
Ranunculus adoneus
Bloomer's buttercup, straight-beak buttercup, swamp buttercup
alpine buttercup
sometimes fleshy and ± tuberous.
slender, 0.8-1.4 mm thick.
nearly erect or decumbent, never rooting nodally, hispid, strigose, or glabrous, base not bulbous.
erect from large caudices, 9-25 cm, glabrous, each with 1-3 flowers.
blades 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.
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.
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.
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.
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.
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.
n = 16.
Ranunculus orthorhynchus
Ranunculus adoneus
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.)
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.)
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
