Bernhard Adalbert Emil Koehne (February 12, 1848 – October 12, 1918) was a German botanist and dendrologist born near Striegau, a town known today as Strzegom, Poland.
Koehne was a professor of botany in Berlin and was a leading authority of the plant family Lythraceae. In Adolf Engler's treatise Das Pflanzenreich ("The Plant Kingdom"), he was author of the chapter on Lythraceae. He also made important contributions involving Lythraceae to Engler and Karl Prantl's Die Natürlichen Pflanzenfamilien ("The Natural Plant Families"), as well as to Karl Friedrich Philipp von Martius' Flora Brasiliensis.
Another noted written effort by Koehne was the 1893 Deutsche Dendrologie ("German Dendrology"). The plant genus Koehneola (family Asteraceae) is named in his honor.