The California Floristic Province is located along North America's Pacific coast. This biodiversity hotspot is a zone of Mediterranean-type climate and is characterized by hot, dry summers and cool, wet winters.

The region contains a wide variety of ecosystems, including sagebrush steppe, prickly pear shrubland, coastal sage scrub, chaparral, juniper-pine woodland, upper montane-subalpine forest, alpine forest, riparian forest, cypress forests, mixed evergreen forests, Douglas fir forests, sequoia forests, redwood forests, coastal dunes and salt marshes. Today, a quarter of the original vegetation remains in more or less pristine condition.

The hotspot is home to the Endangered giant sequoia (Sequoiadendron giganteum), the planet's largest living organism and its taller but less massive relative, the Endangered coastal redwood (Sequoia sempervirens). A number of threatened endemic species are found here, too, including the Endangered giant kangaroo rat (Dipodomys ingens), the desert slender salamander (Batrachoseps major aridus) and some of the last individuals of the Critically Endangered California condor (Gymnogyps californianus). The hotspot is the breeding ground for this very large bird that is now expanding to Arizona and Utah in the United States of America.