German botanist, born in Freiburg. Herzog's chief interest was in bryophytes, which he collected widely between 1904 and 1911. He thereafter spent 28 years as Professor of Botany at the University of Munich, before moving to Jena. At an early age, Herzog became interested in the plantlife of his locality, the Black Forest, especially in mosses. He published his first piece of work on bryophytes aged 18, going on to study sciences at Freiburg and Zurich and gaining his doctorate from the University of Munich in 1903. His first plant collecting trips were to Sardinia (1904 and 1906), then Ceylon (now Sri Lanka) in 1905 and 1908. Two expeditions to Bolivia followed in 1907-1908 and 1910-1912. The year after his return, he married Gertrud Locherer in Freiburg, with whom he had three children. He was appointed Professor of Botany at Munich from 1920 to 1925, then at Jena, where he remained until 1948. Herzog was an expert on exotic mosses, publishing works on the specimens he found on his travels and Geographie der Moose in 1926. Many species are named in his honour including Collania herzogiana Kraenzl., Cyathea herzogii Rosenst. and Dioscorea herzogii R. Knuth.