President Thomas Jefferson, an avid, inquisitive gardener as well as a political leader, wanted desperately to know what lay west of the Mississippi River. He had traveled to Europe several times before his presidency, bringing back seeds and plants he nurtured in his gardens at Monticello. He introduced American gardeners to the Brandywine tomato, Tom Thumb lettuce and hyacinth bean vine, among many other contributions.
As early as 1792, Jefferson had been considering what lay out West beyond the boundaries of the country. He contemplated what natural wonders might be there, what routes might be found to the west, what trade could be established, and what flora and fauna might flourish there.
When the Louisiana Purchase was signed, even before Congress had officially ratified the deal, Jefferson directed his personal secretary, Meriwether Lewis, and Lewis’ friend, William Clark, to lead an expedition. The president wrote detailed directions and suggestions to Lewis before the Corps of Discovery embarked on its mission in 1804.
In addition to emphasizing the importance of making friendly contact with the natives, scouting locations for military forts and finding potential sites for new towns and cities, Jefferson directed Lewis and Clark to record the plants they encountered, as well as the animals and people.
Lewis and Clark’s journals recorded more than 300 new species of animals, including flocks of the now-extinct Carolina parakeet, cited in vast numbers along the Missouri River near what is now Independence and Kansas City. They recorded discovering the Osage orange tree (Maclura pomifera) on the west bank of the Mississippi River in March of 1804. Using their journals and maps to trace their route, you soon discover that the Missouri River has been altered. Once a multi-channel, meandering river, it is now confined within much narrower banks.
Although the river’s course has been straightened, many of the plants remain much as they were in Jefferson’s time. You can find medicinal plants and herbs that have grown for thousands of years. The willow, used for easing headaches, still grows rampant there. So do blackberries and raspberries, used for food and medicine. Smartweed, mayapple, pokeweed, cardinal flower and many others were present at that time, used primarily for medicine by the native people and later by the pioneers.
Many plants found along the route today would not have been present during the Corps’ expedition. The Corps of Discovery opened up a vast section of the United States to settlement, and with that expansion came new varieties of plants and animals.
Some examples of plants not found during the time include white sweet clover (Melilotus alba) and plaintain (Plantago major), found in yards all across the United States. Plants we take for granted as purely American, both were imported from Europe and spread through grain crops as settlers moved west. Horehound and catnip, often found growing in the wild, were carried as medicinal plants and escaped from cultivation after Lewis and Clark’s time. Velvet leaf (Abutilon theophrasti), a native of India and considered by early physicians to be useful in treating dysentery, fever and stomachaches, is now considered a noxious weed by most American farmers and also spread across the nation after Lewis and Clark.
Walking or driving the expedition’s route today yields an experience of then and now. Lewis and Clark saw an unimaginable variety of flora throughout their adventure and realized Jefferson’s dream of discovery. The process of changes in the landscape continues to this day.
Jim Long writes from his home in the Ozark Mountains and is author of several books on gardening and historical subjects.