I see quite a bit of these type of plants around, so it is good to know that they are Buttercup (Ranunculus) and are poisonous upon consumption. This one is very similar to the Allegheny Mountain Buttercup (Allegheny Crowfoot) (Ranunculus allegheniensis). The beaks of the achenes (seeds) on Allegheny Mountain Buttercup are 5 times longer (0.6-1.0 mm) and strongly curved/hooked. The beaks of the achenes of this plant are closer to 0.1-0.2 mm. See bottom several images below. Even though the back of some of the sepals (green petals surrounding the flower) is hairy (see closeup below) as would be Allegheny Mountain Buttercup, without the long, hooked achene beaks, I think this must be Kidney-Leaved Buttercup.
