Taxonomic and nomenclatural needs of National Plant Germplasm System (NPGS) are now met through GRIN by botanists of the National Germplasm Resources Laboratory (NGRL) which is responsible for the taxonomy area of the database. GRIN TAXONOMY includes all accepted family and generic names from throughout the world. By necessity all 391 specific and infraspecific taxa represented by germplasm in the NPGS are also included in this taxonomy, although that represents only about a quarter of all accepted names from these ranks in GRIN. A broad range of economically important plants are treated by GRIN nomenclature, including food or spice, timber, fiber, drug, forage, soil-building or erosion-control, genetic resource, poisonous, weedy, and ornamental plants. Most or all species of important agricultural crop genera are represented in GRIN; for other less economic genera only a portion of the species may be represented. When all species of a genus are represented in GRIN this is indicated by a comment in the GRIN genus report. Reference to the literature cited in GRIN may provide information relating to the treatment of other species.

The taxonomy area encompasses names governed by the International Code of Nomenclature for algae, fungi, and plants (ICN; McNeill et al., 2012). Names treated under the International Code of Nomenclature for Cultivated Plants (Brickell et al., 2009), such as cultivars, may be linked to individual accessions in the accession area of GRIN. These cultivar or other designations are provided only to the extent that they are represented by germplasm accessions. Their inclusion and verification is the responsibility of the site where the germplasm is maintained.