W.Zimm.

Walter Max Zimmermann (May 9, 1892 – June 30, 1980) was a German botanist and systematist. Zimmernann’s notions of classifying life objectively based on phylogenetic methods and on evolutionarily important characters were foundational for modern phylogenetics. Though they were later implemented by Willi Hennig in his fundamental work on phylogenetic systematics, Zimmermann's contributions to this field have largely been overlooked. Zimmermann also made several significant developments in the field of plant systematics such as the discovery of the telome theory. The standard botanical author abbreviation W.Zimm. is applied to species he described.

Walter Zimmermann was born in Walldürn, Germany. He began his collegiate studies in 1910 at the University of Karlsruhe and later transferred to University of Freiburg in 1911. After transferring between the institutions of Friedrich Wilhelm University and University of Monaco and serving in World War I, he returned to the University of Freiburg where he completed his PhD degree in 1920. Zimmermann became a scientific assistant at the University of Freiburg’s Botanical Institute. At the University of Tübingen he taught as a private lecturer from 1925 to 1929, as an adjunct associate professor from 1929-1930, as an associate professor from 1930-1960, and as a full professor of botany from 1960 until retirement, and died in Tübingen in 1980. Throughout his lifetime he received numerous awards such as Honorary member of the Zoological-Botanical Society in Vienna, Honorary Member of the Association of German Biologists, and the Serge von Bubnoff Medal of the Geological Society of the GDR (1961), the Federal Service Cross, First Class (1962), and the Merit Medal of the State of Baden-Württemberg (1978).

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