Mead's Milkweed (Asclepias meadii Torr) Collected by Ralph E. Brooks in Douglas County, Kansas, June 8, 1982, unknown maker from the United States

An herbarium is a systematically arranged collection of preserved plants. The R. L. McGregor Herbarium houses approximately 400,000 specimens collected over the past 150 years. These include dried plant specimens (exsiccatae), seeds, and boxed and fluid-preserved vascular plant specimens. The herbarium also houses the largest single collection of plants from the grassland biome of central North America, as well as the largest collections of lichens and vascular plants from Kansas.

Common throughout much of the United States outside of the Southwest region, Milkweed is important for pollinators, and its foliage is a substantial food source for Monarch Butterflies and other insects. Mead’s Milkweed, once common in the Midwest, is a rare variety that is now on the endangered species list.