Melilotus albus

Melilotus albus, known as honey clover, white melilot (UK), Bokhara clover (Australia), white sweetclover (US), and sweet clover, is a nitrogen-fixing legume in the family Fabaceae. Melilotus albus is considered a valuable honey plant and source of nectar and is often grown for forage. Its characteristic sweet odor, intensified by drying, is derived from coumarin. Melilotus albus is of Eurasian origin but can now be found throughout the subtropical to temperate zones, especially in North America, and is common in sand dune, prairie, bunchgrass, meadow, and riparian habitats. This species is listed as an "exotic pest" in Tennessee, "ecologically invasive" in Wisconsin, and a "weed" in Kentucky and Quebec....read more on Wikipedia.