Although the Manual was published only 10 years ago, it is rapidly becoming out-of-date as a result of the phenomenal progress in plant systematics. Some significant taxonomic changes have already been made and others are on the horizon; it is estimated that 57% of the families in the 1993 edition of The Jepson Manual will require substantial revision.

At this time, revised taxonomic treatments are not available for most groups and therefore botanists are forced to use outdated and incomplete references when identifying plants. Because accurate plant identification is essential to guide responsible land use and conservation decisions, the revision of outdated treatments, to reflect new insights on plant relationships, diversity and distribution, is an urgent priority.

The Jepson Herbarium has initiated a five-year project (2003–2008) to produce a scientifically revised Jepson Manual. The Second Edition will provide:

• A new philosophy that encourages the recognition of monophyletic groups (natural lineages) and cryptic biodiversity (where taxa cannot be distinguished morphologically but lineages have been identified using molecular or other non-morphological data)



• Revised treatments for all taxa in the 1993 edition of the Manual (~72% of the families in the 1993 edition of The Jepson Manual will require substantial revision and ~250 genera will be treated in a different genus and therefore have new names)



• New treatments for taxa that have been added to the flora of the state since 1993: Native taxa that are new to science (92 names under consideration) Native taxa that were not previously known from California (27 taxa) Non-native taxa that are recently naturalized (111 confirmed additions; 227 under consideration)



• Updated and corrected geographic information



• Corrected authors for ~800 plant names



• Revised as well as new, additional illustrations (with a special emphasis on invasive plants)



• Addition of flowering times



• New references to the California Natural Diversity Database and the California Native Plant Society



• New references to the California Department of Food and Agriculture, Integrated Pest Control Branch



• Full integration with an extensive set of online resources: electronic version of the Manual; Index to California Plant Names; Jepson Online Interchange for California Floristics; Consortium of California Herbaria; electronic, interactive, multiple-entry, identification keys (MEKA); horticultural database; point distribution maps; and photographs of most taxa).

Marking a new era in California floristics, the Second Edition of The Jepson Manual and the online companion material will be the most comprehensive, scientifically accurate sources of information on the California flora.

Completion of the Second Edition will depend on the generosity of donors who share the Herbarium's interest in pursuing Dr. Jepson's vision of documenting and preserving California's environmental and botanical riches.

For more information on the benefits of being a Friend—

For more information about the Jepson Flora Project's Donor Opportunities—

For more detailed information on the Production of the Second Edition (1.7 megabyte PDF document file)—