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