Sonoma Spineflower

Chorizanthe valida

Sonoma spineflower is a California endangered plant species, which means that killing or possessing the plant is prohibited by the California Endangered Species Act (CESA). Sonoma spineflower is also listed as endangered under the federal Endangered Species Act. Sonoma spineflower is an annual herb in the buckwheat family (Polygonaceae). It blooms with a head of white to rose-colored flowers from June to August. It grows in well-drained, sandy soils of coastal grassland prairies in Marin County.

Sonoma spineflower was thought to be extinct for 77 years until a population was rediscovered in Abbot’s Lagoon at the Point Reyes National Seashore (PRNS) in 1980. PRNS has done extensive work to protect and encourage Sonoma spineflower by installing experimental seed plots of 1,000 seeds each in an effort to establish new colonies. PRNS has monitored the population and seen fluctuations in the population, but no significant decline. In 2009, the United States Fish and Wildlife Service awarded PRNS a $58,850 Preventing Extinction grant. PRNS used this grant to remove invasive plants, move a road that fragmented Sonoma spineflower habitat, collect seeds to use in reintroduction plots, and collect soils for analysis.

Current threats to Sonoma spineflower may include trampling, grazing, invasive species, and climate change. Preventing the encroachment of invasive velvet grass (Holcus lanatus) is necessary to protect Sonoma spineflower. Efforts need to be made to maintain current populations and increase their size. The success of the reintroduction plots at PRNS suggests that further expansion of the Abbot’s Lagoon population is possible.

CDFW may issue permits for Sonoma spineflower pursuant to CESA, and you can learn more about California laws protecting Sonoma spineflower and other California native plants on the CDFW website. Sonoma spineflower occurs in CDFW's Inland Bay Delta Region. More information is also available from the U.S. Fish and Wildlife Service Species Profile for Sonoma spineflower.

Updated 6/29/2017

round, pink flower
Chorizanthe valida, photo copy; Brad Kelley
line drawing of round flower - click to enlarge in new window
Chorizanthe valida, CDFW Illustration by Mary Ann Showers, click for full-sized image