Walter H. Lewis, professor emeritus of biology in Arts & Sciences at Washington University in St. Louis, died peacefully at his home in St. Louis on Nov. 17, 2020. He was 90.
A world expert on the wild roses of North America, he was honored in 2013 by the American Rose Society as a “Great Rosarian of the World.” Lewis studied and conducted research in many botanical topic areas, including systematics and taxonomy, cytology, palynology, ecology, ethnobotany and pharmacology.
Lewis and his wife, Memory Elvin-Lewis, professor emerita of biology at Washington University, were frequent collaborators on projects around the world, including on notable ethnobotanical work with Indigenous peoples of Peru. Their book, “Medical Botany: Plants Affecting Man’s Health,” is recognized as a definitive work on traditional pharmacopeias and their relevance to modern life. Lewis was lauded by international societies for his efforts to include and recognize the contributions of Indigenous people in the process of discovery.
He also was awarded the Martin de la Cruz Silver Medal from the Mexican Academy of Traditional Medicine in 2000, the E.K. Janaki Ammal Gold Medal from the Indian Ethnobotanical Society in 2004 and was named, along with his wife, a Distinguished Economic Botanist from the Society for Economic Botany in 2006.
Lewis earned bachelor’s and master’s degrees in biology and botany from the University of British Columbia (UBC), Vancouver, and his PhD in biology from the University of Virginia. Prior to his work at Washington University, he taught at Stephen F. Austin State University in Texas and completed postdoctoral studies at the Royal Botanic Gardens, Kew, in the United Kingdom and the Swedish Academy of Sciences, Stockholm. Lewis also received honorary degrees from UBC, the University of Waterloo in Ontario and Andrews University in Michigan.
Lewis joined Washington University in 1964; he retired as a professor of biology in 2000. He taught popular classes in botany for undergraduates and also served as the university ethnobotanist. As professor emeritus, Lewis continued his active research program, publishing his last technical paper in 2017 at age 87.
Lewis maintained a concurrent appointment as senior botanist at the Missouri Botanical Garden. Between 1964 and 1972, he was curator and director of the herbarium at the garden. Lewis served as editor and principal investigator for the Flora of Panama. His decades-long taxonomic study of roses culminated in the publication of Volume 9 of the Flora of North America, which his collaborators dedicated to him. Lewis is credited with collecting more than 23,000 plants worldwide and at least a dozen plant species are named in his honor.
In addition to his wife, Lewis is survived by a daughter, Memoria Lewis (Trevor Morse); a son, Walter Lewis Jr. (Joanna Wyatt); and grandchildren Florence, Lilian and Leander. The family is planning a celebration of life for June, when the roses in his experimental garden at home will be blooming.