Johannes Peter Müller
He studied medicine at the University of Giessen, and in 1839 furthered his education in Berlin as a student of physiologist Johannes Peter Müller (1801–1858). In 1842 he earned his habilitation at Giessen, where he worked as a private lecturer. During this time his focus turned exclusively to botany, and in 1853 he became a professor of botany and director of the botanical gardens at Giessen. He maintained these positions until his death in 1891.