The National Plant Germplasm System of the Agricultural Research Service, U.S. Department of Agriculture maintains a computer database, the Germplasm Resources Information Network (GRIN), for the management of and as a source of information on its 18.974 germplasm accessions. The taxonomic portion of GRIN provides the classification and nomenclature for these genetic resources and many other economic plants on a worldwide basis. Included in GRIN TAXONOMY are scientific names for 27.417 genera (14.399 accepted) and 1.414 infragenera (1.352 accepted) and 110.129 species or infraspecies (63.860 accepted) with common names, geographical distributions, literature references, and economic impacts. Generally recognized standards for abbreviating author's names and botanical literature have been adopted in GRIN. The scientific names are verified, in accordance with the international rules of botanical nomenclature, by taxonomists of the National Germplasm Resources Laboratory using available taxonomic literature and consultations with taxonomic specialists. Included in GRIN TAXONOMY are federal- and state-regulated noxious weeds and federally and internationally listed threatened and endangered plants. Since 1994 GRIN taxonomic data have been searchable on the World-Wide-Web.