29 November 1857 – 30 September 1937
The German botanist Franz Niedenzu spent most of his career as professor and later rector of the Lyceum Hosianum in Braunsberg, East Prussia (now Braniewo, Poland), where he also founded a botanical garden. He contributed nine family treatments to "Die natürlichen Pflanzenfamilien." His own herbarium, which includes a reference collection of fragments provided by the Berlin Herbarium, is now incorporated in the holdings of the New York Botanical Garden. In many instances, these fragments are all that remains of type material lost in the destruction of the Berlin Herbarium during World War II.
Much of Niedenzu's work was focused on Malpighiaceae. He was hampered by a lack of opportunity to see the holdings of some important herbaria, especially the Jussieu herbarium, a paucity of collections from many parts of South America, and the poor condition of many specimens that were available to him; yet, he produced a series of insightful papers that reveal his keen eye and thorough understanding of the family.
Niedenzu published several generic monographs and papers on related topics in the house journal of his home institution (see Literature) and wrote the section on Malpighiaceae for "Die natürlichen Pflanzenfamilien" (1888–91, 1897, 1906). His studies culminated in the masterly second monograph of the Malpighiaceae, family no. 141 in "Das Pflanzenreich" (1928).