In his 1803 directive outlining his goals for the expedition, President Thomas Jefferson instructed Meriwether Lewis to record "the soil & face of the country, it's growth & vegetable productions, especially those not of the U.S. [and] the dates at which particular plants put forth or lose their flower, or leaf."
Lewis had been taught by his mother, a lay healer, about the medicinal properties of plants. And as part of his expedition preparations, Jefferson had sent him to Benjamin Smith Barton, a lecturer at the University of Pennsylvania and author of the first botany text published in the United States. Under Barton's tutelage, Lewis learned how to preserve and label flora. (He would bring back more than 200 plant specimens, which are preserved at the Lewis and Clark Herbarium at the Academy of Natural Sciences in Philadelphia.)
In March 1804, while Lewis was in St. Louis attending the LouisianaTerritory transfer ceremonies, he sent Jefferson a shipment of botanical specimens, including live Osage apple cuttings (Maclura pomifera, now known as the Osage orange). Though they did not survive, some samples Lewis collected in 1807 did, and as Susan H. Munger writes in Common to This Country: Botanical Discoveries of Lewis and Clark, "trees growing in Philadelphia and at the University of Virginia are said to be direct descendants of the cuttings sent back by Lewis."
The Osage orange, which Lewis obtained from Pierre Chouteau, a former Indian agent, was probably the espedition's most significant botanical discovery. The plant's long thorns created a virtually impenetrable hedge, and later in the 19th century, many thousands of miles of these trees would be planted as frontier fencing. The fragrant tree held its popularity as a barrier until it was eclipsed by barbed wire in the 1880s.
St. Louis March 26th 1804.
I send you herewith inclosed, some slips of the Osages Plums, and Apples. I fear the season is too far advanced for their success. Had I earlyer learnt that these fruits were in the neighbourhood, they would have been forwarded at a more proper time....I obtained the cuttings, now sent you, from the garden of Mr. Peter Choteau, who resided the greater portion of his time for many years with the Osage nation....
The Osage Apple is a native of the interior of the continent of North America, and is perhaps a nondiscript production; the information I have obtained with respect to it is not so minute as I could wish, nor such as will enable me to discribe it in a satisfactory manner. Mr. Peter Coteau...obtained the young plants at the great Osage vilage from an Indian of that nation.... The general contour of this tree, is very much that of the black haw, common to most parts of the U. States....So much do the savages esteem the wood of this tree for the purpose of making their bows, that they travel many hundred miles in quest of it. The particulars with respect to the fruit, is taken principally from the Indian discription; my informant never having seen but one specimen of it, which was not fully ripe, and much shrivled and mutilated before he saw it. The Indians give an extravigant account of the exquisite odour of this fruit when it has obtained maturity, which takes place the latter end of summer, or the begining of Autumn. They state, that at this season they can always tell by the scent of the fruit when they arrive in the neighbourhood of the tree, and usually take advantage of this season to obtain the wood....An opinion prevails among the Osages, that the fruit is poisonous, tho' they acknowledge that they have never tasted it. They say that many anamals feed on it, and among others, a large species of Hare which abounds in that country. This fruit is the size of the largest orange, of a globular form, and a fine orange colour....
I have the honour to be with sincere esteem Your Obt. Servt.