That attractive buttercup-like flower is actually an invasive ground cover called Lesser Celandine that is taking over and choking out everything in its way! As pretty as it is, it should be dug out carefully as it has many small tubers. Do not put in yard waste bags. As with Garlic Mustard, this invasive plant should not be collected with regular yard waste that will go to a composting facility but should be sent straight to a landfill. Info and photo here. It is most likely NOT marsh marigold and should not be confused with Celandine Poppy which is a non-invasive midwest native alternative.
Download SWANCC’s eco-landscaping guide here.