Missouri Botanical Garden’s Peter H. Raven Library is globally recognized as one of the most comprehensive libraries of botanical literature in the world. Vital to the Garden’s mission is "to discover and share knowledge about plants and their environment, in order to preserve and enrich life." While the collections focus on plant names and descriptions, the Library is also rich in other subjects such as the study of edible and medicinal plants, the art of botanical illustration, and the history of scientific exploration, and includes more than 250,000 items. (Wikipedia)