This post illustrates a couple of dozen, common species of spring wildflowers in Ohio. The scientific name in each caption links to an article where you can learn more about that species (a Wikipedia article, if possible). It also lists the months in which you can expect to see each species bloom in central Ohio. In southern Ohio they will bloom a little earlier and in northern Ohio a little later.
Cutleaf Toothwort
The photo below shows some of the foliage.