The chickweed oxytheca (Oxytheca caryophylloides) is a homebody of western Riverside County. This native Californian plant is an endemic annual herb that only grows in the mountains of southern Sierra Nevada, Ventura County, the San Gabriel Mountains, and western Riverside County. This little chickweed has been mapped in various locations along State Route 243 and near Idyllwild in the San Jacinto Mountains at elevations between 4,000 and 8,500 feet. It prefers sandy soils in yellow pine forest habitats and can grow up to 20 cm tall.

The chickweed oxytheca blooms from July to September and sprouts small 1- 2 mm flowers in clusters of two to three. The flower petals range in color from green to yellow to red. Their tiny seeds are golden to red-brown and measure 1.2 to 1.5 mm in length.

Although not well-known or easily recognizable, this plant is essential to western Riverside County’s unique landscape and habitats. The chickweed oxytheca is threatened by urbanization and development, as well as logging and recreational activities-emphasizing the importance of staying on established trails. To protect the species from becoming threatened or even endangered, the MSHCP has described 18,660 acres of suitable habitat for this species within the San Jacinto Mountains and foothills for conservation. Conserved habitat will protect this species and potentially enable it to expand into other areas of suitable habitat.