Contra Costa Wallflower
Contra Costa Wallflower
Erysimum capitatum var. angustatum
|Listed||April 26, 1978|
|Description||Monocarpic perennial with lanceshaped leaves and yellow or orange flowers.|
|Habitat||Antioch Dunes; windblown sand.|
|Threats||Habitat loss, competition with introduced plants.|
Contra Costa wallflower, Erysimum capitatum var. angustatum, puts up a single branched stalk, 12-40 in (30.5-101.6 cm) tall, bearing lance-shaped to more elongated leaves. Yellow or orange flower-heads are grouped in a terminal raceme. The wall-flower is described as a monocarpic perennial, meaning that plants die after setting seed. Most plants set seed in the second year.
This species seems to be restricted to stabilized dunes of fine sand with some clay associated with sparse herbs and shrubs, some pasture grasses, herbs, and scattered live oaks. It prefers river fronting cliff faces and edges.
A 1983 survey estimated that about 700 Contra Costa wallflower plants survived, but annual surveys conducted since that time have shown strong fluctuations in numbers. In 1984, 818 plants were counted; in 1985, 786; in 1986, 1,492; in 1987, 2,204; in 1988, 845; and in 1989 the population rebounded to 1,752 individuals. The low count in 1988 was due partially to a wildfire on the western half of the refuge and partially to trampling of the habitat.
A research population has been cultivated at the Tilden Regional Park Botanical Garden and the East Bay Botanical Gardens.
Industrialization and sand mining along the river, wildfire, and human intrusion (agricultural conversion to vineyards and grazing, power line right-of-ways, and off-road vehicles) have destroyed or degraded much of the original dunes. In the wake of these disturbances, common weedy plants have invaded, displacing native species.
Conservation and Recovery
To assist the recovery of the Contra Costa wall-flower, remaining habitat must be protected. To this end a portion of the dunes has been purchased and added as a satellite to the San Francisco Bay Area Wildlife Refuge. Interpretive signs have been installed, and firebreaks built to reduce the risk of uncontrolled fire. Recovery may also require selective use of herbicides to control encroaching plants.
U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
Eastside Federal Complex
911 N. E. 11th Ave.
Portland, Oregon 97232-4181
Telephone: (503) 231-6121
U. S. Fish and Wildlife Service. 1984. "Revised Recovery Plan for Three Endangered Species Endemic to Antioch Dunes, California." U. S. Fish and Wildlife Service, Portland.