Alternate name: Sand-dune Wallflower, Plains Wallflower
Family: Brassicaceae, Mustard view all from this family
Description Rough, hairy stems, sparsely branched above or unbranched, support conspicuous bright yellow or orange flowers.
Habit: native biennial to short-lived perennial herb; single erect leafy stem; highly variable.
Height: 0.5-4 ft (0.15-1.2 m)
Leaf: gray-green; in basal rosette, narrow, spatulate to linear, to 7 in (18 cm) long or more, to 0.6 in (15 mm) wide or more, withering by flowering; on stem, similar, alternate, sometimes shallowly toothed.
Flower: yellow to orange-brown to purple-brown (rarely white), sometimes fragrant, 4-parted, 0.75-1 in (18-25 mm) wide; in dense, widely rounded, terminal cluster, about 3 in (7.5 cm) wide, to 20 in (50 cm) tall.
Fruit: long pod, square cross-section, to 4 in (10 cm) long; held erect or protruding from stem.
Endangered Status The Contra Costa Wallflower, sometimes considered a subspecies of the Western Wallflower, is on the U.S. Endangered Species List. It is classified as endangered in California. The Antioch Sand Dunes are home to the Contra Costa Wallflower. The dunes are a unique environment hosting many plants more commonly found in deserts to the south. The Antioch dune complex is the largest of several such habitats, but it has been considerably reduced in size by sand mining and industrial development. The Antioch Sand Dunes National Wildlife Refuge has been established on 55 acres to protect all of the remaining populations of the Contra Costa Wallflower, in addition to other endangered species.
Flower March to July.
Flower May - July
Habitat Variable: dry open sites; semi-desert, desert, alpine, open shrubland, open woodland, road cuts, meadows, sage scrub, pinyon-juniper woodland, yellow pine forest, chaparral; also cultivated ornamentally.
Range Throughout western and central U.S., from Washington south to California, east to Texas, northeast to Arkansas, Tennessee, Virginia and Maryland, northwest to Ohio, Michigan and Wisconsin, southwest to Iowa, Kansas and Colorado, north to Montana; and Alaska.
Discussion Also known as wallflower, sanddune wallflower, coastal wallflower, pretty wallflower. The latin name Erysimum asperum is also used. Several varieties have been proposed.
Comments Although it is a biennial, western wallflower will usually produce the flowers the first year. Western wallflower is extremely variable in size and flower color. It is similar to the cultivated wallflower (Cheiranthus spp.) and is equally showy in a wildflower garden.
Exposure Preference Sun.
Native Distribution Virginia & Ohio to s.w. Canada, s. to Tennessee, Texas & California; much more common westward
Site Preference Plains; foothills; high elevation coniferous forests
Soil Preference Dry, well-drained soils.