If you venture into wet wooded areas in the springtime, there’s a good chance you’ll find some bright yellow flowers. Buttercups can be difficult to distinguish from one another, and multiple sub-species are commonly known as swamp buttercup. I believe the pictures enclosed below are Ranunculus hispidus (hispid buttercup or bristly buttercup).
Some sources refer to a closely related plant as Ranunculus septentrionalis (swamp buttercup), while other sources no longer distinguish between Ranunculus septentrionalis and Ranunculus hispidus. Both species are native to most of the U.S. and Canada east of the Rocky Mountains.
The Illinois Wildflowers website says of swamp buttercup,
This species often grows in soggy areas of woodlands that are too wet for some invasive species, such as Alliaria petiolata (Garlic Mustard). Therefore, populations of Swamp Buttercup remain reasonably secure. This plant is also able to tolerate some degradation of its habitat from other causes.
Incidentally, now would be a good time to pull up garlic mustard if you come across any in nature.
Follow me after the jump for images of swamp buttercup.