This is a Mauve Bowles Wallflower. It’s my favorite of the Erysimums. There are several colors in this family. In my zone 7 garden, they bloom from March through July. I cut it back after blooming and it puts out another huge display of flowers the next year. The Wallflower was an evergreen in my garden.
Janet over at Queen of Seafood has a yellow variety growing. She writes more about it and has a picture of the Wallflower in her garden.
The picture above is from my pictures of Tanglewood Park in Clemmons, NC.