The Botany Department holdings started as a collection of economically important plants and materials derived from plants that were displayed in the 1893 World's Columbian Exposition. These collections have been added to over the years by researchers in the Department and through the acquisition of important collections from other institutions. Today, the Botany Department has a collection of 2.6 million carefully preserved specimens. These invaluable specimens are used by scientists from throughout the world to study many diverse topics including: investigating the medicinal plants used by indigenous peoples in tropical countries, monitoring the effect of air pollution on forests, finding potential new chemicals and medicines, and understanding the geological history of the earth. Botany Collections: Botany Herbarium | Fungi | Lichens | Algae | Bryophytes | Pteridophytes | Gymnosperms | Flowering Plants | Timothy C. Plowman Economic Botany Collection | Type Photograph Collection