Hickman’s cinquefoil is a California endangered plant species, which means that killing or possessing the plant is prohibited by the California Endangered Species Act (CESA). It is also listed as endangered under the federal Endangered Species Act. Hickman’s cinquefoil is a small herbaceous perennial that develops a woody taproot that can survive through years of unfavorable conditions. Some individuals have been estimated to live 25 to 30 years. Plants reproduce by seed in favorable years, as well as vegetatively by sending out runners.
Only two native populations of Hickman’s cinquefoil are known to be extant at the time of this webpage posting, one in Monterey County, and one in San Mateo County. The population in Monterey County occurs near Pebble Beach in an area designated for day-use, and supports very low numbers of plants. The Hickman’s cinquefoil occurrence in Monterey County has been negatively affected by changes in hydrology from the operation of Spyglass Hill Golf Course. Year-round water flow at this site has allowed invasive species to establish and compete with Hickman’s cinquefoil. Most of the San Mateo County population is owned by the Peninsula Open Space Trust; however, highway construction threatens this population because it partially occurs on land owned by the California Department of Transportation. Other threats to Hickman’s cinquefoil include competition with nonnative species, low recruitment, low population numbers, an altered fire regime, and climate change.
Cooperation with the Pebble Beach Company is necessary to improve habitat conditions for the population in Monterey County and ensure that operations do not negatively affect the population, leading to its extinction. Invasive species also need to be managed at both populations, and research on pollination and reproductive ecology of Hickman’s cinquefoil needs to be completed to assess the reason for its low recruitment rates. Research into outplanting should also be conducted to facilitate population growth.
CDFW may issue permits for Hickman’s cinquefoil pursuant to CESA, and you can learn more about the California laws protecting Hickman’s cinquefoil and other California native plants. Populations of Hickman’s cinquefoil occur in CDFW’s Central and Bay Delta Regions. More information is also available from the U.S. Fish and Wildlife Service Species Profile for Hickman’s cinquefoil.