Purple Prairie Clover

Photo: NPS, Erin Anfinson

In late July 1804, Meriwether Lewis documented his first sighting of the Purple Prairie Clover (Dalea purpurea), a beautiful plant of the plains and prairies.

It’s a member of the bean family and Lewis must have been impressed by the clover because he collected at least three specimen. It was one of the many plants he sent back to President Jefferson in April 1805 when the keelboat returned to St. Louis.

Two of the original specimens have survived the long journey and are today a part of the Lewis and Clark Herbarium at the Academy of Natural Sciences in Philadelphia.

At that time, Purple Prairie Clover was found all across the Great Plains, from Texas to Alberta. It grows best where the mean precipitation is at least 15 inches. It’s a perennial wildflower that can grow from eight to 35 inches tall. It begins growing at the same time each spring as prairie grasses, but it quickly exceeds the grasses in height.