LaDema Langdon  LaDema Mary Langdon (5 January 1893 – April 1977) was an American botanist known for her work on floral anatomy, taxonomy, embryology, and morphology of "Juglandaceae", "Fagaceae". "Cycas", and "Dioon spinulosum". She was a member of the American Association for the Advancement of Science and was a professor at Baltimore Junior College and Goucher College. She earned her bachelor's degree from Oberlin College and her graduate degrees from the University of Chicago.