John Walter Thomson Jr. (1913âÂÂ2009) was a Scottish-born American botanist and lichenologist, sometimes referred to as the "Dean of North American Lichens".
When he was eight years old, Thomson moved with his family to the U.S.A. In 1935 he graduated from Columbia University with a bachelor's degree, majoring in botany and zoology. At the University of WisconsinâÂÂMadison (UW Madison) he graduated in botany with a master's degree in 1937 and a Ph.D. in 1939. After receiving his Ph.D., he worked as a naturalist at Manhattan's American Museum of Natural History and taught at Brooklyn College until 1942. During WW II, he taught topics in military aviation and meteorology from 1942 to 1944 for the U.S. Army Air Corps at Superior State Teachers College (now named the University of WisconsinâÂÂSuperior). In 1944 he became a faculty member of the department of botany at University of WisconsinâÂÂMadison, retiring there in 1984 as professor emeritus. In retirement, he continued to work almost daily at the Madison campus until he was about 88 years old.
Thomson taught for many summers at the University of Minnesota's Itasca Biological Station and Laboratories campus, which is located on Lake Itasca. He collected lichens not only in the Arctic and in Wisconsin, but also in a number of other U.S. states, including "California, Florida, Indiana, Oklahoma, New York, Pennsylvania, and Washington". He was the author or coauthor of over 100 scientific articles. He accumulated a herbarium of lichens, which gave the Wisconsin State Herbarium at UW Madison perhaps the world's best lichen collection of North American and Arctic material. Thomson issued two exsiccatae, namely Lichenes Wisconsinenses exsiccati (1946âÂÂ1960) and Lichenes Arctici (1960âÂÂ1966).
In 1937 in Madison, Wisconsin, Thomson married the botanist and conservationist Olive Sherman. Upon his death he was survived by his widow, three sons, a daughter, and seven grandchildren. Another son, Douglas E. Thomson, M.D., died in 1978 at age 34. As a memorial to Douglas their dead son, John and Olive Thomson gave money to The Nature Conservancy for land acquisition, leading to the establishment of the Thomson Memorial Prairie, which consists of of remnant dry prairie. Dennis Thomson and his wife Joan Schurch Thomson donated land to the nonprofit conservation organization The Prairie Enthusiasts, which created the named Schurch-Thomson Prairie.