Sonoma sunshine is a California endangered plant species, which means that killing or possessing this plant is prohibited by the California Endangered Species Act (CESA). Sonoma sunshine occurs naturally in Sonoma County, and is found in vernal pools and wet grasslands in the Sonoma Valley and the Santa Rosa Plain. Populations of vernal pool plants such as Sonoma sunshine are typically discontinuous and fragmented due to differences in climate, substrate, and topography, and are often restricted to very specific habitats and locations. These factors coupled with the urbanization and conversion of land for agriculture endangers many California vernal pool species with extinction. Sonoma sunshine is a small annual plant that blooms February through April and is sometimes associated with Burke’s goldfields (Lasthenia burkei) and Sebastopol meadowfoam (Limnanthes vinculans) which are also listed as endangered species under CESA. Sonoma sunshine is also listed as an endangered species under the federal Endangered Species Act, and at the time of this page’s posting, the California Natural Diversity Database reported 22 occurrences of this species that are presumed to still exist.
The biggest threat to Sonoma sunshine continues to be urban development and conversion of land to viticulture or other intensive land uses, and the resulting habitat fragmentation. Sonoma sunshine is also sensitive to land use changes that cause variations in hydrology and the duration of vernal pool inundation. Sonoma sunshine is threatened by increased runoff, frequent disking of land, breaking of the vernal pool hardpan, and activities that allow competing plant species to become established. Other threats include manipulation of normal gene flow resulting from restoration work, buildup of thatch in previously grazed areas, and the effects of climate change.
Although work has already begun to conserve this species, further action is necessary to aid the recovery of Sonoma sunshine. Remaining natural populations of Sonoma sunshine should be protected and new populations should be established that do not negatively affect the natural populations. Non-native plant species that compete with Sonoma sunshine should be managed and effective weed eradication measures that do not harm Sonoma sunshine should be researched. Populations of Sonoma sunshine should be monitored using standardized protocols and research into the habitat requirements, reproductive ecology, gene flow, seed bank dynamics, and the long-term viability of restoration sites should be conducted.
CDFW has participated in the following Sonoma sunshine studies and papers through the Cooperative Endangered Species Conservation Fund or other mechanisms:
CDFW may issue permits for Sonoma sunshine pursuant to CESA, and you can learn more about the California laws protecting Sonoma sunshine and other California native plants. Populations of Sonoma sunshine occur in CDFW’s Bay Delta Region. More information is also available from the United States Fish and Wildlife Service Species Profile for Sonoma Sunshine.