Desmodium humifusum

About

Desmodium × humifusum is a species of flowering plant in the legume family known by the common names trailing tick-trefoil, eastern trailing tick-trefoil, and spreading tick-trefoil. It is native to the eastern United States, where it has been reduced to scattered populations in the states of Massachusetts, Connecticut, and Indiana. It once had a wider distribution but it has likely been extirpated from Delaware, Maryland, New Jersey, New York, Rhode Island, Virginia, West Virginia, and Missouri.

Summary from Wikipedia