Ranunculus orthorhynchus
Ranunculus cardiophyllus
Bloomer's buttercup, straight-beak buttercup, swamp buttercup
heart-leaf buttercup, renoncule pédatifide
sometimes fleshy and ± tuberous.
cylindric, 1.3-2 mm thick.
nearly erect or decumbent, never rooting nodally, hispid, strigose, or glabrous, base not bulbous.
erect, 11-53 cm, pilose or glabrous, each with 1-5 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 ovate or elliptic, undivided or innermost 3-5-parted, 2.2-6.9 × 1.8-4.5 cm, base cordate to broadly obtuse, margins crenate with more than 5 crenae, apex rounded to broadly 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 pilose;
receptacle canescent;
sepals 5-8 × 3-7 mm, abaxially pilose, hairs colorless;
petals (0-)5-10, 6-13 × 4-13 mm;
nectary scale ciliate or sometimes 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 or cylindric, 5-16 × 5-9 mm;
achenes 1.8-2.2 × 1.5-2 mm, finely canescent;
beak subulate, curved or straight, 0.6-1.2 mm.
= 32.
Ranunculus orthorhynchus
Ranunculus cardiophyllus
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.)
Ranunculus cardiophyllus is quite variable. Through most of its range, leaves always have rounded marginal crenae and cordate or truncate bases, stems are often densely pilose (but may be sparsely pilose or glabrous), and achene beaks are curved. In plants from Arizona and New Mexico, however, leaves may have obtuse marginal crenae or broadly obtuse bases, stems are never densely pilose, and achene beaks are sometimes straight. Forms showing some or all of these charactersistics are often separated as R. cardiophyllus var. subsagittatus. The characteristics are poorly correlated, however, and taxonomic recognition is not warranted.
Most specimens of Ranunculus cardiophyllus have all of the basal leaves unlobed, but plants with the innermost basal leaf 3-5-lobed are common. A few specimens, mostly from the northern part of its range, have all of the basal leaves 5-parted or -divided. Those plants approach R. pedatifidus in their morphology, and R. cardiophyllus has sometimes been considered a variety of that species.
(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. 
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USDA Plants Database- LBJ Wildflower Center
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