The Trail Companion

Wildflower and Plant Guides
Web and Electronic Resources

While not as useful on the trail as a good field guide, you may also be interested in the following online sites:

Wildflower Hotsheet: This site hosted on the Picture This commercial site features tips on where to find wildflowers across California. The main site also hosts several other similar lists, including "Bay Area Ramblings" - tips on great places to photograph wildlife and landscapes. Nice collection of photos.
Vascular Plants of California: Checklist and distribution maps of taxa covered by the Jepson Manual: Useful in conjunction with the Jepson Manual; requires scientific genus or species name.
CalFlora Database Project: This project hosted by the UC Berkeley Digital Library Project includes four databases on all the 8375 currently recognized vascular plants in California, over 670,000 plant observation records, and over 20,000 photos: Species (search by common, scientific or family name, location, elevation, plant community, etc.), Occurrence (distribution maps, similar to Jepson maps), Synonomyms (find current and older scientific names) and CalPhotos: Plants (search by common or scientific name, location, color, etc.). A search by species usually yields one or more photos, synonyms and maps. Amazing site!

And also of interest:

Dianne Fristrom, John Game and Glen Keator. Wildflowers of the San Francisco Bay Area. Iris Press, 1998.: An interactive CD-ROM containing photos and information on hundreds of Bay Area wildflowers, including detailed locations. Browse by family and species, with information on each family. Also includes fourteen wildflower hikes. See the online site for more information and examples. [suggested by Dave Croker]