Franciscan wallflower or San Francisco wallflower (Erysimum franciscanum), a rare and endemic plant to California, can be seen growing in coastal scrub and in sandy and rocky bluffs in the Bay Area. Once common throughout San Francisco, it has become rare due to development and loss of habitat. The fragrant flowers vary in color from cream to yellow and have four petals, forming a cross shape. This cross shape of four petals is a characteristic of the whole family and is the reason for its old name, Cruciferae, now the Brassicaceae or Mustard Family.
The mustard family, Brassicaceae, contains many of the common foods we enjoy, sometimes referred to as cruciferous, such as cabbage, broccoli, and of course mustard. However wallflower is not known to be edible. (Caution eating wild plants without proper identification is not safe).
Franciscan wallflower is a short-lived perennial, generally one to two feet in height. It produces cardenolides, a ‘juice’ on certain parts of the plant which makes it taste bitter to protect it from predators. The leaves of Franciscan wallflower are broad with sharp deep teeth. Franciscan wallflower generally blooms from March to June, but can start blooming as early as January.
Franciscan wallflower grows from Santa Cruz County to Sonoma County. Its population is discontinuous and sightings of it are considered rare. It can be found in coastal areas on dunes, and serpentine and sandy soils, preferring open space. It is able to adapt to harsh conditions, and is not as able to compete with other plants in more favorable conditions; making it susceptible to negative impacts from competition from invasive plants.
Franciscan wallflower can be grown easily in Bay Area gardens, does well in full sun, and prefers well drained soils. Wallflower attracts bees and butterflies. It grows well with other small perennials such as buckwheat, checkerbloom, and seaside daisy.
Sources 1. The Biogeography of the San Francisco Wallflower, online.sfsu.edu/bholzman/courses/fall01%20projects/sf wallflower.htm 2. Erysimum franciscanum/California Flora Nursery, https://calfloranursery.com/plants/erysimum-franciscanum 3. San Francisco Wallflower, http://calscape.org/Erysimum-franciscanum- (San-Francisco-Wallflower)?srchcr=sc567d2dec967ed 4. https://www.calflora.org/cgi-bin/species_query.cgi?where- calrecnum=3480