Goat's Rue or Devils Shoestrings if you prefer

This beautiful flower is just starting to bloom in the Dunes. A member of the pea family, Goat's Rue was previously fed to goats because it was thought that the plant increased milk production.

The plant is no longer fed to animals and it has been found to contain rotenone; a fish and insect poison.

It is also called Devils Shoestrings due to a trait that will become quite apparent if you ever find yourself trying to remove it from your yard; it has very long, very stringy roots.  

source: Audubon Wildflowers