Flora of North America species comparison

Ranunculus fascicularis is very similar to R. hispidus var. hispidus, and herbarium specimens without underground parts may be difficult to identify. Ranunculus fascicularis grows in drier habitats; segments of its leaves are commonly oblanceolate and blunt, with few or no marginal teeth; and its petals are widest at or below the middle. Ranunculus hispidus var. hispidus is usually larger in all its parts (leaves, flowers, heads of achenes); leaf segments are variable in shape but their apices are normally sharper and their marginal teeth more numerous, and petals are widest above the middle.

(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.)