George Engelmann, internationally noted St. Louis botanist, physician, and meteorologist is known primarily for his studies on cacti, oaks, grapes, and other plants. In St. Louis he helped establish two scientific organizations and two botanical gardens – the first of their kind west of the Mississippi – of which the Academy of Science of St. Louis and the Missouri Botanical Garden still survive.

The roots of Opuntia fulgida were chewed for treatment of diarrhea. However, besides the beneficial features of this plant it has been reputed to have an array of adverse affects: mental disturbances, pain in the eye, nausea, diarrhea, coldness, pain in the joints, etc.

ENGELMANN, GEORGE JULIUS (1809-1884). CACTACEAE OF THE BOUNDARY.
St. Louis: s.n., 1858.
(Washington University, Becker Library)