I'm lichen this article.
http://www.jsonline.com/news/wisconsin/acquisition-of-rare-lichen-collection-lands-wisconsin-in-worlds-top-tier-b99363974z1-278176631.html
Madison They have been stepped on and ignored for millennia, but at the Wisconsin State Herbarium, lichens are loved. So well-liked, in fact, when herbarium director Ken Cameron had a chance to acquire a rare and valuable collection of 60,000 lichen specimens from a German collector recently, he snapped them up. Suddenly Wisconsin's lichen collection rose to around 180,000 specimens, putting the facility in Birge Hall on the University of Wisconsin-Madison campus in the top 1% of the world's plant repositories.
Lichens actually are an important part of the world's ecosystem. Because they grow slowly at a regular rate, they can be used to date calamities, such as earthquakes. Many are sensitive to environmental changes and can reveal air pollution levels and changes in the ozone layer. They're eaten by certain animals, such as caribou and reindeer. "They've been used as a 'canary in a coal mine' environmental indicator," Cameron said. Anything that comes out of the Earth's atmosphere can accumulate in lichens, said Tom Nash, a retired lichenologist and Arizona State botany professor who volunteers at the Wisconsin State Herbarium.
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The collection of German lichenologist Klaus Kalb is rich in tropical and European samples, while Wisconsin's is heavily weighted toward lichens collected from temperate zones and the arctic. With the acquisition of Kalb's collection, which includes lichens from Africa, South America and Australia, Wisconsin now has around 70% of the world's known lichen examples.
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Wisconsin naturalist Increase Lapham, considered the state's first great scientist, donated the first 1,000 plant specimens he had collected in the state. From those plants, the Wisconsin State Herbarium's holdings have grown to 1.2 million items, ranging from leaves and prairie grasses to mosses and lichens.
If interested, there will be an open house at the Wisconsin State Herbarium 6:30 to 8 p.m. Oct. 23 at Birge Hall on the University of Wisconsin-Madison campus. Authors Martha Bergland and Paul G. Hayes will be there to discuss their book, "Studying Wisconsin: The Life of Increase Lapham".