This paper pursues the lead of Bat? K. Holland in utilizing classic li
terature as a guide to the pharmacologic potentialities of natural pro
ducts. Instead of focusing on European texts, however, American medici
nal plants are examined through the work Of the influential naturalist
Constantine S. Rafinesque (1783-1840). Rafinesque is discussed with s
pecial attention to his activities as a medical botanist. In particula
r, the plant species monographed in the main section of his Medical Fl
ora of the United States (1828-1830) are studied for their historical
and current use as medicinal agents. The results are tabulated and pre
sented in a bar graph. The study concludes that Rafinesque was a progr
essive therapist whose Medical Flora is a promising guide for phytopha
rmacuetical prospecting with North American plants.