Western Wallflower
Erysimum capitatum
Family: Brassicaceae
This extremely variable plant 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, or tangerine-colored, but plants in some populations may have red, white or purple flowers. This can be a short-lived perennial in drier locations, or a larger (up to 3’ tall) plant that can live over 5 years. Plants reseed readily.
Full sun to bright shade, low to regular water and hardy to about 0°F.
Larval food plant for many butterflies including the cabbage white (Pieris rapae), the large marble (Euchloe ausonides), and the sara orangetip (Anthocharis sara).
This species has been used for medicine pretty much wherever it is native, both topically and internally.
Photo by Paul Rothrock, SEINET
Erysimum capitatum on iNaturalist
Erysimum is from the Greek eryomai, to help or save, referring to the medicinal properties; capitatum means head-like, referring to the dense rounded cluster of flowers at the top of each stem. There are 286 species native to temperate Eurasia, North Africa and Macaronesia, and North America south to Costa Rica. There are a few more native to Arizona, but this species is by far the most showy.
Found on open slopes, from 3,000-9,500 ft. widely distributed throughout the western and midwestern United States, barely getting into Canada, and south into northern Mexico.
A darker orange specimen captured by Sue Carnahan, SEINET
Most specimens in Arizona are yellow, photo by Gregory Gust, SEINET