Willow monardella is a California endangered plant species, which means that killing or possession of plants collected from the wild is prohibited by the California Endangered Species Act (CESA). The species is also listed as endangered under the federal Endangered Species Act. Willowy monardella is a perennial herb with a strong minty fragrance. It generally grows in clumps of one to four plants, and has compact, rose to light-purple flower heads. Willowy monardella has only been found in San Diego County, where it grows in sandy bottoms or banks of ephemeral washes in coastal sage scrub and riparian shrub communities.
There were 28 historic and extant occurrences of willowy monardella listed in the California Natural Diversity Database at the time of this webpage posting; however, according to a status review completed by the U.S. Fish and Wildlife Service that is published in the final Critical Habitat Designation Final Rule in 2012, only eight natural occurrences still exist. Willowy monardella has consistently decreased in its range and population numbers in recent decades.
The main threats that willowy monardella faces are habitat destruction and alteration caused by development, erosion and altered hydrology, habitat degradation and conversion from fire, invasive plants, and vulnerabilities associated with its limited range and population sizes. Threats from habitat destruction have decreased slightly because seven willowy monardella occurrences are now protected under the San Diego Multiple Species Conservation Plan; however, habitat alteration remains a significant threat. Altered hydrologic conditions have resulted in larger flood events than the species experienced in the past, and these flood events threaten willowy monardella and other riparian plants. These flood events, along with alterations in natural fire regime, and proximity to human activities have also allowed nonnative plant species to become a significant threat to willowy monardella.
Willowy monardella occurrences should be more closely monitored to determine current status and observe population trends. Surveys should also be conducted for new occurrences of willowy monardella throughout its range. Management of willowy monardella habitat, including flood control and erosion prevention, is essential to ensuring that current occurrences do not continue to decrease in population numbers. Reintroduction of willowy monardella into previously occupied habitat or introduction of the species into new habitat should be explored, and a viable seed bank should be maintained to facilitate reintroduction.
CDFW may issue permits for willowy monardella pursuant to CESA, and you can learn more about the California laws protecting willowy monardella and other California native plants. Populations of willowy monardella occur in CDFW’s South Coast Region. More information is also available from the U.S. Fish and Wildlife Service Species Profile for willowy monardella.