From back cover:

The flora of Monterey County is one of the largest and most varied in CA, the result of the county's large size, the diversity of its climate and topography, and it's complex geology.  Plant communities range from lush redwood forests along the coast (which reach their southern limit here), to the giant sugar and ponderosa pine forests of the higher elevations in the Santa Lucia Range and the near desert scrubs of the dry southeastern part of the county.  The flora includes over 2300 taxa in 142 families, and some 20 species that are endemic to Monterey County; this is more than are found in many entire states.  The well-illustrated field key provides an unusual opportunity for amateur and professional botanists alike to improve their knowledge of the diverse flora of the county and to appreciate and conserve it.  This new edition adds hundreds of new plants, incorporates a very large number of changes to families and scientific names, and corrects some previously unnoticed errors.