Western Riverside County Supports Largest Remaining Population of Rare Spreading Navarretia
The spreading navarretia, a hairy annual herb, is our latest MSHCP Species Spotlight. The rare, flowering species looks like something from another planet with a stem measuring about 6 inches tall and leaves that turn spiny and sharp when dry. Its Latin name is Navarretia fossalis.
The plant blooms with white or purple flowers in May and June from a clump of tiny seeds that remain stuck together until they become wet, and then separate into a sticky clump.
The plant is rare to spot. In 1998, it was listed as a federally threatened species, but the number of known occurrences has grown since that time. Native to western Riverside County, it can also be found in northwestern Los Angeles County and to the south in San Diego County and Baja California. Riverside County supports the largest remaining population of the spreading navarretia.
The plant grows near vernal pools and ditches where water collects. It can be found most often in salty clay soils in the Hemet area of the MSHCP. It also has been spotted along the San Jacinto River from just west of Mystic Lake to the Perris Valley Airport.
The MSHCP includes 6,900 acres of suitable habitat for conservation in grasslands, playas, and vernal pools within the San Jacinto River, Mystic Lake, Salt Creek, Skunk Hollow, and Santa Rosa Plateau. The species is threatened by habitat destruction and fragmentation from urban and agricultural development, changes to floodplains, drought, and flooding.