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Common Name: Western Wallflower
Scientific Name: Erysimum capitatum
Synonyms: Erysimum asperum
Family: Mustard Family (Brassicaceae)
Distribution: common and widely distributed in the Intermountain West
Habitat: foothill and middle montane habitats
Habit: biennial or short-lived perennial herb
Foliage Color: deep green
Leaves: mostly in a basal rosette, lance-shaped, coarsely toothed
Flower Color: bright yellow
Flower Form: cross-shaped flowers 0.5-0.9" in diameter, borne in showy, elongate, terminal clusters
Flowering Season: mid to late spring
Cultural Requirements: Prefers full sun to partial shade in rich to well-drained soils. Fully cold-hardy. Drought hardy (i.e., needs no supplemental water after establishment on the Wasatch Front), but somewhat tolerant of overwatering.
Culture: Difficult to obtain from direct late fall seeding. Seeds are largely nondormant. Seedlings might establish more readily from an early fall or spring seeding. Plants produced as container stock and planted out in spring grow quickly but do not flower until the second year. They may or may not live to flower in subsequent years, depending possibly on seed source or cultural conditions.
Uses and Notes of Interest: This plant is somewhat similar to the closely related cultivated wallflower (genus Cheiranthes). Western wallflower has larger, more attractive flowers, which also have a lovely fragrance that resembles that of sweet pea. On the minus side, it has a short flowering season and is not reliably perennial. For those into butterfly gardening, this plant is a great butterfly attractor. The seeds are small and are borne in long pods (siliques), which must be picked before they split open in order to collect seeds.