Horkelia tenuiloba is a species of flowering plant in the rose family known by the common names Santa Rosa horkelia and thin-lobed horkelia. It is endemic to California, where it is known only from the coastal hills and mountains north of the San Francisco Bay Area. It is a plant of chaparral habitat. This is a perennial herb producing a low mat of hairy, glandular green foliage around a woody base. The leaves are cylindrical or...