Joseph Kern Mertzweiller was a Louisiana Iris enthusiast and former Exxon research scientist. He was an important figure among iris growers for over forty years. Mertzweiller was born in 1920 in New Orleans, Louisiana. He received an engineering degree from Loyola University in 1941, and a master’s degree from the University of Detroit in 1943. He served in the U.S. Navy during the Second World War and was employed as a research scientist by the Exxon corporation. He retired from Exxon in the 1980s.

During the 1950s, Mertzweiller became interested in the Louisiana Iris as a result of his close association with two botanists who specialized in them, Claude Davis and Ira Nelson. In the 1950s, Mertzweiller began conducting his own hybridizing experiments. He specialized in “tetraploid Louisianas.” Among the new varieties he hybridized were Colorific, President Hedley, Just Helene, and Cajun Sunrise.

Mertzweiller was also very active in a number of organizations devoted to the Louisiana Iris in particular and irises in general. Among these organizations were the Society for Louisiana Irises, the American Iris Society, the Louisiana Society for Horticultural Research, and the Louisiana Iris Society of America. Mertzweiller was a very avid participant in iris shows for many years serving often as a judge.

Over the years, Mertzweiller developed innumerable friendships with others interested in irises. He engaged in extended correspondence with many of these individuals. The correspondence series contains over forty folders. Mertzweiller worked with Marie Caillet on a Louisiana iris book sponsored by the Society for Louisiana Irises.