United States botanist from Collinsville, Illinois who grew up in Cuero, Texas. Cornelius Herman Müller, or Mueller, trained in botany at the University of Texas, Austin (BA 1932, MA 1933) and the University of Illinois, Urbana (PhD 1938). He divorced his first wife Mary Elizabeth Taylor in 1936, changed his surname to Muller in 1937, and in 1939 married Katherine Kinsel.

Neil Muller worked as a assistant botanist (1938-1942) for the United States Department of Agriculture and in 1942, during the Second World War, joined a special research team seeking alternative sources of rubber and working with Guayule (Parthenium argentatum A. Gray). In 1945 he was appointed Assistant Professor of Science at the Santa Barbara College, later (1958) a campus of the University of California. He became Assistant Professor of Botany in 1948, Associate Professor of Botany in 1950, full Professor in 1956 and was acting dean of the Graduate Division (1961-1962). At this time he was one of the first scientists to be involved in the Institute for Tropical Biology in San Jose, Costa Rica (1961-1962). His wife Katherine became director of the Santa Barbara Botanical Garden (1951-1974).

As a plant taxonomist, C.H. Muller was a specialist on American oaks, Quercus and published on the genus in Southwestern United States and Mexico, travelling to remote areas on horseback. Plant collections used for his research and to aid teaching plant taxonomy became the founding collections of the UCSB herbarium. His research increasingly concentrated on ecological observations including vegetation dynamics, plant interactions and his classic studies of chemical interactions or allelopathy. He published extensively on both desert and arctic ecosystems, providing his own interpretation of vegetation climaxes, and demonstrated the importance of hybridisation in the systematics of American oaks. In 1975 he was awarded the Eminent Ecologist Award, the highest honour of the Ecological Society of America. He became and Emeritus Professor in 1976. Two oak species were named after him: Quercus cornelius-mulleri Nixon & K.P. Steele from California and Quercus mulleri Martínez from Mexico. The Cornelius H. Muller Archives are deposited in the Museum of Systematics and Ecology at UCSB.

Sources:
N. Vivrett et al, 1998, "Cornelius H. muller", University of California, In Memoriam, 1998: 121-123
R.H. Whittaker. 1975, "Eminent Ecologist, 1975, Cornelius H. Muller", Bulletin of the Ecological Society of America, 56: 23-24.