Strong representation of neotropical taxa is credited to the many floristic projects and collection-oriented research programs, an integral part of the department since its inception. Especially rich are holdings in the neotropical families Rubiaceae, Asteraceae, Palmae, Fabaceae, Piperaceae and Solanaceae, primarily due to the work of present or former staff botanists. The Central American material is overall one of the world's finest single collections with special strengths in Guatemala, Honduras and Costa Rica. The South American collections are important with special strengths in Venezuela, Colombia, Ecuador and Peru. A good representation in North American taxa is found, especially for Missouri and Illinois, and unmarked types are commonly discovered in these holdings.