The current ISTA List of Stabilized Plant Names represents the 5th edition of this work. Previous editions were completed and published in 1966, 1983, 1988, and 2001. Individual names on the List are stabilized for a period of at least six years. Because numerous changes were made for the 2001 edition, the ISTA Nomenclature Committee thereafter refrained from proposing changes to any name, regardless of its initial date of stabilization, until 2007. Although only six years have elapsed since the last edition many changes or adjustments in nomenclature for the plants treated therein have occurred. These mostly result from recent advancements in taxonomic classification or from the nomenclatural actions of an International Botanical Congress, the latter reflected in the 2006 International Code of Botanical Nomenclature (Vienna Code) (ICBN) adopted by the 2005 Vienna Congress (J. McNeill et al., Regnum Vegetabile 146, A. R. G. Gantner Verlag, 2006).
In preparation for this new edition, several reports containing items for possible change from the previous edition were prepared by the Nomenclature Committee Chair, by consulting the taxonomic data of the Germplasm Resources Information Network (GRIN), and made available to Committee members on the Web. These reports included:
The items included in these reports were evaluated individually by Nomenclature Committee members. The resulting Nomenclature Committee Ballot, also made available on the Web, summarizes the results of Committee voting. From these results, a document containing the "Proposed Changes to the ISTA List of Stabilized Plant Names" approved by Committee vote was submitted to and approved by the 28th ISTA Congress in Iguassu Falls, Brazil in 2007.
The approved list of changes includes 256 entries that detail changes to 246 names, or around 8.7%, of the 2835 included in edition 4 of the Stabilized List. They involve 1 spelling change, 50 changes to authorship of names, 40 changes in linkage between synonyms and correct names, 62 changes in family classification, acceptance of 36 names formerly treated as synonyms, addition of 41 new accepted names and 22 new synonyms, reduction of 62 formerly accepted names to synonymy, and conversion of one entry from a binomial to a monomial. Those changes (57) impacting the International Rules for Seed Testing were made available to the Rules Committee for incorporation into Edition 2008, to be published simultaneously with this document.
The current edition thus includes 2898 entries, comprising 2370 accepted names and 528 synonyms, and representing 191 different vascular plant families. Since ISTA stabilization has thus far been extended only to names at species rank or above, the acompanying list consists mostly of binomials, although it now includes 21 trinomials among its synonyms. In the Stabilized List two different methods are employed in linking synonyms to their correct names, depending upon the relationship between them. An equals ("=") sign links the two names when either infraspecific categories (i.e. subspecies or varieties) are not recognized under the accepted binomial or the synonymy is to the typical element. For example, Phaseolus lathyroides = Macroptilium lathyroides (no infraspecific categories recognized), or Dichanthium ischaemum = Bothriochloa ischaemum (actually B. ischaemum var. ischaemum). However, when the synonymy is to an accepted non-typical element, even when this is only a cultivar, the phrase "included in" precedes the accepted name. For example, Brassica campestris "included in Brassica rapa" (as subsp. campestris) or Erica maweana "included in Erica ciliaris" (as the cultivar 'Maweana').
A few names include Group epithets, the formation of which is covered under the International Code of Nomenclature for Cultivated Plants (C. D. Brickell et al., Acta Horticulturae 647, International Society for Horticultural Science, 2004). The remaining names conform to the latest (2006) edition of the ICBN. Since the ICBN authorizes usage of alternative names for several vascular plant families, both alternatives are provided in the accompanying list, and usage of either one is acceptable. Such alternative family names include Compositae/Asteraceae, Cruciferae/Brassicaceae, Gramineae/Poaceae, Guttiferae/Clusiaceae, Labiatae/Lamiaceae, Leguminosae/Fabaceae, Palmae/Arecaceae, and Umbelliferae/Apiaceae. The ICBN also standardizes its author abbreviations in conformity with R. K. Brummitt and C. E. Powell, Authors of Plant Names (Royal Botanic Gardens, Kew, 1992), now updated on the Web, and this practice is followed here as with the 4th edition.
Although the ICBN no longer requires this, in the accompanying list the complete authorship is presented for all names. To provide some understanding of its various components, a brief explanation of authorship is provided here. In a given author string the original author's or authors' name(s) appear in parenthesis when later author(s) transferred the original species or infraspecies to another genus or rank, thereby creating a new combination of epithets. For example, Tristania conferta R. Br., upon transfer to the genus Lophostemon, becomes L. confertus (R. Br.) Peter G. Wilson & J. T. Waterh. When "ex" connects two sets of authors, the first author(s) proposed a name but did not validly publish it as required by the ICBN; later the second author(s) validly published the name while crediting the first author(s). For example, when validly published by George Bentham, the name Mimulus cardinalis was credited to David Douglas, who collected and named the specimen Bentham used to publish his description of the plant, thus we have M. cardinalis Douglas ex Benth. When citing authorship for such cases only the publishing author need be included (i.e., the author(s) preceding the "ex" may be omitted, e.g. M. cardinalis Benth.), although for completeness both are provided in the Stabilized List.
GRIN's taxonomic data have been a substantial asset in the compilation of the Stabilized List. Although the data yielding this compilation reside in GRIN, they exist apart from GRIN Taxonomy and the content of these data reflects only what has been approved by ISTA and its Nomenclature Committee. Nevertheless, in the web version of this document linkages to the extensive data in GRIN Taxonomy on common names, native distribution, economic impacts, and literature references for the names on the list have been included, although it will be apparent to those who pursue those links that some of the names in GRIN Taxonomy have differing treatments. In fact, a report of all such differences, or searches of these names by taxonomic or other criteria, is available in GRIN. As already mentioned, this report was of considerable benefit in locating nomenclature items for consideration by the Nomenclature Committee in the preparation of our proposals to the Iguassu Falls Congress of 2007, thereby providing for increased harmonization with the nomenclature of the Association of Official Seed Analysts (AOSA) of North America, which has adopted GRIN Taxonomy as its nomenclatural standard.
The Nomenclature Committee Chair thanks the following members for their contributions to this document, namely Bernard R. Baum, Kees van Ettekoven, Niall Green, Doris Groth, Wilbert L. A. Hetterscheid, Charles E. Jarvis, Maria Rosaria Mannino, Klaus Pistrick, and Michel Porcher. The Committee gratefully acknowledges the contributions of Doris Groth, as well as the staff of the ISTA Secretariat, for assistance in presenting the Nomenclature Committee Report pertaining to this document to the 2007 Ordinary Meeting of ISTA. Gratitude is also due to Steve Jones, the Rules Committee Chair, for accommodating the tardily submitted changes reflected in this document into the 2007 Proposed Rules Changes, and to the ISTA Secretariat for assistance with hardcopy publication of this document. And finally, the Chair thanks his home institution, the Agricultural Research Service of the United States Department of Agriculture (USDA-ARS) and its Germplasm Resources Information Network, without whose support this work would not have been possible.