Small-Flowered Buttercup is one of the most common Ranunculus spp.
in Illinois. The flowers aren't very showy and this plant is easily overlooked. There are many Ranunculus spp.
in the state and they are often hard to tell apart. While attempting to identify Small-Flowered Buttercup, look for lower leaves that are orbicular, kidney-shaped, or deeply 3-lobed with crenate margins, and slender upper leaves with mostly smooth margins. The foliage is usually hairless, although there is an uncommon form of this plant that is finely pubescent. Small-Flowered Buttercup is very similar in appearance to Ranunculus micranthus
(also called Small-Flowered Buttercup); the latter species is restricted to the southern half of Illinois. To distinguish Ranunculus abortivus
from Ranunculus micranthus
, it is often necessary to examine the naked receptacles of these two species (the receptacle of the flower is what remains after the carpels, sepals, and petals are removed). The receptacle of Ranunculus abortivus
is pubescent, while the receptacle of Ranunculus micranthus
is hairless. Another difference is the following