Ranunculus rhomboideus
Ranunculus cardiophyllus
Labrador buttercup, prairie buttercup, prairie crowfoot
heart-leaf buttercup, renoncule pédatifide
slender, 0.8-1.8 mm thick.
cylindric, 1.3-2 mm thick.
erect, 5-22 cm, pilose or occasionally glabrous, each with 3-12 flowers.
erect, 11-53 cm, pilose or glabrous, each with 1-5 flowers.
persistent, blades ovate to rhombic, undivided or rarely innermost 3-parted, 1.1-5.3 × 0.9-3.6 cm, base obtuse, margins crenate with 5 crenae, apex rounded.
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.
pedicels pilose;
receptacle pilose;
sepals 4-6 × 1.5-3 mm, abaxially pilose, hairs colorless;
petals 5, 6-8 × 2-4 mm;
nectary scale glabrous.
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.
depressed-globose, 4-6 × 5-7 mm;
achenes 1.8-2.2 × 1.2-1.8 mm, glabrous;
beak slender, curved, 0.2-0.3 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.
= 16.
= 32.
Ranunculus rhomboideus
Ranunculus cardiophyllus
In addition to the range given above, L. D. Benson (1948) cited nineteenth-century specimens from Quebec, New York, Massachusetts, and Rhode Island. No modern specimens have been seen from those areas.
(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.)
BC
IL Wildflowers
MI Flora
MN Wildflowers
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
WA
Flora NW
