Shortly after Meriweather Lewis reached St. Louis in 1803 to plan for his voyage to the Pacific with William Clark, he prepared his first packet of flora and fauna from west of the Mississippi and dispatched it to President Jefferson. The cuttings, which were later planted in Philadelphia and Virginia, were supplied by Lewis's new French friend, Pierre Chouteau, who took them from a tree growing in the garden of his mansion. One of the best-known...