Index to California Plant Names
Thomas J. Rosatti, Editor

    The Index to California Plant Names (ICPN) includes names from a variety of sources (e.g., specimens, checklists, floras) that have been applied, correctly or incorrectly, to California plants. Approximately 9,400 of 15,000 names presently included in ICPN appeared in The Jepson Manual as accepted names, names of minor variants, or synonyms; most of the remainder have come into use, or come back into use, correctly or incorrectly, since The Jepson Manual. The primary intention is to account for names people are likely to encounter, from whatever source, and to summarize the status of such names with respect to the first printing of The Jepson Manual (TJM), and to the flora of California as it is understood presently by authors contributing to the Second Edition of The Jepson Manual (to the extent that we are incorporating any changes these authors make relative to TJM as we become aware of them). New names for taxa already known to occur in the state, reports of taxa previously known to science but not known from California, the publication of names for taxa new to science, and many other kinds of changes or potential changes appear in the literature of botany much more frequently than floras are published, or even more frequently than updated floristic treatments appear online. Activity that has the potential to change the list of accepted names for plants occurring outside of cultivation in California appears in the Index to California Plant Names as soon as we become aware of it, so that ICPN is as current as any such comprehensive resource can be. Decisions whether or not to accept the potential changes to this list are made by the authors contributing to the Second Edition of The Jepson Manual.    

Scientific Name

Partial names are allowed (e.g., Seq gig). You can retrieve all species in a genus by entering a genus name only.
When entering infraspecific names, do not include the words "var.", "subsp.", or "f.".

Additional searches are available on the Jepson Online Interchange page.
    Each entry in ICPN includes the scientific name with author citation, the family in which the taxon is included according to classification adopted by the Jepson Flora Project (i.e., that used in The Jepson Manual, as updated by advances made in plant systematics subsequently), an “Initial Editorial Analysis,” and an “Editorial Summary and Current Status.” Most names in ICPN come directly from The Jepson Manual, and for the majority of these no changes have been proposed. For these, the “Initial Editorial Analysis” consists of nothing more than an indication that the “Source of the Report for California” is The Jepson Manual. Under “Editorial Summary and Current Status,” such cases include an indication of Current Status (e.g., JFP-1, accepted name for taxon native to California; JFP-2a, taxonomic or nomenclatural synonym for taxon naturalized in California; etc.), and an indication of the “Current Status Authority” (The Jepson Manual). Each entry in ICPN also includes links to the International Plant Name Index (IPNI; The Plant Names Project, 1999) and Tropicos (Missouri Botanical Garden); some include links to various external websites, as appropriate, including the CNPS Rare Plant Inventory, the WEEDS database, Flora of North America North of Mexico, Volume 3 (Nixon & Muller, 1997), and various monographic websites (e.g., Barbara Ertter's “Native California Roses”).    
    Entries for names that have come into use, or that have come back into use, subsequent to The Jepson Manual (names that ultimately may or may not represent changes relative to The Jepson Manual), are fewer in number, but each one is more extensive. In these entries, the “Initial Editorial Analysis” includes “Source of Report for California,” as well as, under “Initial Editorial Comments,” a statement about how or if the name was used in one or more of the various treatments of the flora of California (e.g., Hickman, 1993; Kartesz & Meacham, 1999; Munz, 1959, 1968). Under “Editorial Summary and Current Status,” “Editorial Summary” is an attempt to summarize, in a more or less standardized way, whether the name is or is likely to be accepted or rejected as a name representing a native or naturalized plant in California (i.e., as part of the flora), followed by a statement summarizing the status of the name relative to The Jepson Manual (e.g., addition, for taxon described since TJM; possible addition, minor variant in TJM; probable rejection, infraspecific taxa not recognized in TJM). “Editorial Summary” is an attempt to provide users with a quick way to put the name in context relative to The Jepson Manual, and allows us to compute estimates of the kinds and numbers of changes that have been proposed or confirmed since The Jepson Manual.    
    Whereas “Editorial Summary” includes a statement of the status of a name relative to The Jepson Manual, “Current Status” is a statement of the status of a name relative to the flora of California as we understand it currently, a more absolute concept; the two are not equal. For example, names with an “Editorial Summary” that reads "addition, for taxon described since TJM" and one that reads "addition, in different genus since TJM" may both have a “Current Status” category of JFP-1, accepted name for taxon native to CA. Conversely, names with the same “Editorial Summary” statements (e.g., "addition, in different genus since TJM") may have different “Current Status” categories (e.g., for Tetraneuris acaulis (Pursh) Greene, JFP-1, accepted name for taxon native to CA, or, for Pericallis hybrida B. Nord, JFP-2, accepted name for taxon naturalized in CA).    
    Some of the changes that have been proposed or confirmed since The Jepson Manual result from changes in taxonomic philosophy, either on the part of individual specialists regarding their particular group or groups, or on the part of the Editors of the Jepson Flora Project regarding plant systematics and the flora of California as a whole. Refinements in philosophy have been adopted in light of the importance of floristic information to the management of biodiversity in California, as such information is gathered and managed at UC/JEPS; one of these refinements has to do with ever changing ideas about the relationship between evolution and classification in plants. Opinions do and probably always will vary on this subject, but an attempt is being made within the Jepson Flora Project to recognized only groups in which all members have evolved from a single, common ancestor (i.e., to recognize only monophyletic groups), insofar as is practical and to the extent that data bearing on this matter are available. Such a philosophy is in keeping with modern systematic practice as well as with the needs of society for classifications that are predictive; that is, that allow us to predict or suspect characteristics (e.g., medicinal uses) of a plant by understanding its true, genetic, evolutionary relationships. This criterion for recognition of taxonomic groups is not new, and it was certainly applied to some extent in The Jepson Manual. What is new is the extent to which it now is being applied in the classifications we employ.    
    The entries in ICPN for Constancea nevinii (A. Gray) B. G. Baldwin and Eriophyllum nevinii A. Gray are examples of changes that have been confirmed since The Jepson Manual, and that have resulted at least in part from this increased emphasis on monophyly. In short, investigations by Baldwin (1999) indicate that not all species included in Eriophyllum in The Jepson Manual evolved from a single, common ancestor (i.e., that Eriophyllum as circumscribed in The Jepson Manual is polyphyletic). In particular, phylogenetic analyses of evidence from morphology, cytology, and ribosomal DNA indicate that Eriophyllum nevinii appears to be the sole representative of a lineage that diverged from related genera long ago, and that it therefore should be placed in its own genus. Since such a genus had never before been named and described, it was up to Baldwin to do so. He took the opportunity to name his new genus Constancea B. G. Baldwin, in honor of the late Professor Emeritus Lincoln Constance, world-renowned plant systematist (Ertter, 2001), who had not only studied Eriophyllum as a dissertation topic (under Willis Linn Jepson), but recognized E. nevinii as a particularly distinct species even then (Constance, 1937).    
    Many of the entries in ICPN for names that may or may not represent changes relative to those used in The Jepson Manual have elicited contributions from users of the Jepson Online Interchange, including but not limited to the specialists who contribute taxonomic treatments of the plant groups involved. These appear under “Correspondence and Comments Subsequent to Initial Analysis” as “Correspondence.” Each “Correspondence” is given sequentially a number (e.g., Correspondence 1), the date and contributor are indicated, the comments are stored in the database but not actually displayed, and the Editor provides “Editorial Comments” with the same number (e.g., Editorial Comments 1). Such “Editorial Comments” include summary and paraphrasing of the contribution, as well as a statement about the effects that the information has or might have on the “Editorial Summary and Current Status,” which are adjusted (or not) as appropriate.