German-American botanist, physician, and meteorologist best known for his botanical monographs. Engelmann earned his M.S. degree from the University of Würzburg, Germany, in 1813. His most important study was of the Morphology of Monstrosities. He immigrated to the United States in 1833. A pioneer in his field, his efforts included the discovery of immunity in the North American grape to the plant lice Phyllaxera.