Erysimum capitatum is a species of wallflower known commonly as the sanddune wallflower, western wallflower, or prairie rocket. It is a mustard-like plant with thin, erect stems growing from a basal rosette and topped with dense bunches of variably colored flowers. Flowers are most typically bright golden, yellow, tangerine-colored, but plants in some populations may have red, white or purple flowers. Each flower has four flat petals. Seed pods are nearly-parallel to the stem. Although quite variable in appearance, it is an attractive garden plant. There are several natural variants of this plant. Each is treated separately, with certain variants considered endangered species in some areas. For example Erysimum capitatum var angustatum, the Contra Costa wallflower, is an endangered plant in the state of California.