Wildflowers of Southern California
Contains photographs of wildflowers of the southern California chaparral, desert, mountains, and north coast indexed according to scientific, common, or family names.
California Native Plant Society
The California Native Plant Society (CNPS) is a statewide non-profit organization of amateurs and professionals with a common interest in California's native plants.
The Arizona State University Plant Herbarium is the second largest in the Arid Southwest, having over 240,000 mounted specimens.
Southern California Ethnobotany: historical use of native plant southern California ethnobotany: historical use of native plants