Calflora Great Places to view California Native Plants:
CNPS Chapter: San Diego
Tom Chester - Trail Guides for Southern California locations, organized by Jepson Bioregion
The California Chaparral Institute, Escondido
Wild Plants in San Diego County Native Plants, by lifeform Native Plants at the edge of their range non-Native Plants by Jepson Bioregion: Peninsular Ranges Sonoran Desert South Coast
What Grows Here? -- a county level flora --