University of Wisconsin-Madison Herbarium, founded in 1849, is a
museum collection of dried, labeled plants of state, national and
international importance, which is used extensively for taxonomic
and ecological research, as well as for teaching and public service.
It contains the world's largest collection of Wisconsin plants,
about one-third of its 1,000,000 specimens having been collected
within the state. Most of the world's floras are well represented,
and the holdings from certain areas, such as the Upper Midwest,
eastern North America and western Mexico, are widely recognized
as resources of global significance. Here is more
information regarding the Wisconsin State Herbarium.