The University of Wisconsin-Madison Herbarium (WIS), now also officially the Wisconsin State Herbarium
, was founded in 1849, and is a museum collection of pressed, dried, labeled, and classified plants. It also preserves notes, illustrations, and other material that will yield information about plants, and it maintains its own valuable Herbarium Library and Herbarium Map Collection.
The collection of more than 1.1 million specimens is of regional, national, and international importance. It is used extensively for taxonomic and ecological research, as well as for teaching and public outreach. Approximately one-fourth of its vascular plant specimens are from Wisconsin, all of which have been databased. In addition, most of the world's floras are well represented, and the holdings from certain areas such as the Upper Midwest, eastern North America, western Mexico, and the Arctic (primarily lichens) are widely recognized as resources of global significance.