Paysonia stonensis (syn. "Lesquerella stonensis") is a species of flowering plant in the mustard family, known by the common name Stones River bladderpod. It is endemic to Tennessee in the United States, where it is limited to Rutherford County. It grows only in the floodplains of the Stones River, and certain tributaries.
The floodplains of the river that flows through Tennessee is amazingly the only place for a mustard plant to grow.
This is written in the statement that this plant only grows by the river.