California contains 5,047 plant species which represent 32 percent of the total number of plant species in the United States with 2,153 endemic to the state. (Source: Atlas of the Biodiversity of California). These plants are all organisms within the taxonomic kingdom Plantae, many of which use energy from the sun to produce sugar, through a process called photosynthesis. Plants are vital to life on earth, because the photosynthetic process produces oxygen.

Plants are characterized by whether or not they have a vascular system. The vascular system transports water and plant nutrients through vascular tissues throughout the plant. Vascular plants are members of the subkingdom Tracheobionta, these include ferns, club mosses, angiosperms (flowering plants) and gymnosperms(non-flowering plants). Non vascular plants include plants such as algae, fungi, liverworts and mosses.

Common photosynthetic organisms of the kingdom Plantae include:

Vascular Plants

• Angiosperms (Magnoliophyta)
  Angiosperms reproduce by flowers, which are modified shoots that surround immature seeds inside.
  
  
• Ferns and Fern Allies (Pteridophyta)
  Ferns are nonflowering plants that reproduce by spores, which are produced on the underside of the green leafy structures called fronds. Fern allies are similar to ferns in that they also reproduces by spores, but differ from true ferns in that they do not have the same leaf structure.
  
  
• Gymnosperms (Coniferophyta)
  Gymnosperms are nonflowering plants that reproduce by seeds that are enclosed in cones. Some of the largest and longest living organisims in the world are cone-bearing gymnosperms such as pines, firs and redwoods.

Nonvascular Plants

• Algae
  Algae and photosynthetic microorganisms are ecologically important, especially considering they make up half of the photosynthetic production of global organic matter. The microflaura are important food sources, but when there is a high concentration of nitrogen or phosphorous they can cause the water body to become eutrophic. This can lead to low levels of oxygen that are harmful to fish.
  
  
• Fungi and Lichens
  Fungi function as an extensive network of threads existing in organic matter. They secrete enzymes that decompose organic material, which results in a recycling of materials that other organisms can use. Lichens are symbiotic organisms that are a combination of a green algae or cyanobacteria and filamentous fungi.
  
  
• Liverworts and Mosses (Bryophyta)
  These are primitive photosynthetic plants that reproduce by means of spores instead of seeds.  They are often found growing on rocks and trees, with the ability to absorb nutrients directly into their leaves and stems.

The California Department of Fish and Game maintains the threatened and endangered plant species list as part of their responsibility under the California Endangered Species Act. Currently, 218 species and subspecies of plants are listed as either threatened or endangered by the State of California or the federal government.

Other California plant resources include:

• The Biogeographic Information and Observation System is a geospatial mapping application that visualizes biological and ecological data from across the state.
• Calflora is a searchable digital library of wild California plants for use in conservation, education, research, and appreciation.
• CaprICE is an online mapping interface for the vascular plant species that show patterns of plant diversity, distribution ranges of individual plant species, and vegetation associations.
• The Consortium of California Herbaria Search Page is a gateway to over 1.1 million records of vascular plant specimens housed in the herbaria of the 16 participating California institutions within the consortium.
• The Guide to the Trees of Kern County provides photographs, habitat descriptions, and other information about 127 tree species and subspecies including 80 native species, 22 subspecies, and 26 exotic.
• The Napa Vegetation Map provides detailed spatial data layers and Alliance, Class, and Formation level vegetation maps for this county.

Species of Greatest Conservation Need Find out more about California Plants of Greatest Conservation Need.