This landmark volume contains the most complete listing and presentation of the plant specimens collected by the Lewis and Clark expedition. All but one of the plants were collected by Meriwether Lewis, the expedition’s botanist. The collection, how-ever, was nearly lost over the years when it was scattered among various botanists who intended to catalog the expedition’s scientific discoveries. Fortunately, for many years the specimens have been in the care of major institutions, principally the Academy of Natural Sciences in Philadelphia. The 239 extant items are brought together in one book for the first time. This indispensable volume will assist researchers and enthusiasts hoping to identify each plant’s date and place of collection and other information such as plant habitat and ethnobotanical use.