Duke Herbarium houses nearly 400,000 specimens of vascular plants, including 821 types. The collection is especially rich in accessions from the Southeastern United States, in particular for the Carolinas, and Mesoamerica. The vascular plant herbarium contains an important collection of over 22,000 sheets from La Selva in Costa Rica.
Angiosperm families are arranged in linear sequence following APG II (Angiosperm Phylogeny Group II). Within each family, the genera are sorted alphabetically. Each genus is sorted into geographical regions in color-coded folders. Within each geographic region, the species are sorted alphabetically. Unidentified specimens are filed at the end of each category.