Ohio's prairies provided early Native American tribes such as the Miami, Ottawa, and Potawatomi with abundant food and medicine. Deer, otter, bear, beaver, and the now extinct woods bison lived in and around the prairies, and Miami hunters sometimes burned the grass around a herd of bison to drive the animals through a narrow opening where braves waited with bows and arrows. Prairie plants also served medicinal purposes: wild bergamot leaves were boiled to treat pimples and colds, and the root of the purple coneflower was used for ailments ranging from snakebites to distemper in horses; modern medicine still uses extracts from this plant to treat wounds and sore throats. European settlers at first believed the prairies had poor soil because they lacked trees and because wooden plows broke in the tough tangle of roots. In 1835, Cyrus P. Bradley recalled riding across long grass, horned cattle, and what he called gloomy, unhealthy prairies that produced disease, mosquitoes, and rattlesnakes. Only after the iron plow appeared in the 1840s did settlers realize that prairie soil was actually rich in nutrients and well suited for agriculture.