Walter Tennyson Swingle (1871-1952)
United States Department of Agriculture
Freeze of 1894
The Botany of Citrus & It’s Relatives of the Orange Subfamily
Walter Tennyson Swingle was born in Canaan, Pennsylvania, on January 8, 1871. He moved with his family to Kansas two years later. Swingle graduated from the Kansas State Agricultural College in 1890, and studied in Bonn, Germany from 1895-96. He then joined the United States Department of Agriculture. One of Swingle’s first tasks was a survey of citrus growing areas in Florida. This began a long and productive career in citrus biology, including work investigating sub tropic fruits, crop physiology, and breeding. His work in Florida ended temporarily with the 1894 freeze. At that time Swingle conducted studies on citrus and plant anatomy in Europe and the Mediterranean countries including North Africa and Asia Minor. Swingle’s travels resulted in the introduction of the date palm, pistachio nut, figs, and other useful plants into California. Traveling also to Asia, Swingle also brought back 100,000 Chinese volumes on botany to the Library of Congress. He originated the Citranges, a hardy citrus fruit which is a hybrid of the sweet orange and the trifoliate orange. The purpose was to try and create an orange tree that was stronger against colder weather conditions.
Swingle conducted much of the pioneer research that introduced many new principles and knowledge to the citrus industry. He is the author of many books and papers on the origin, physiology, and botany of citrus. He was considered the world’s leading authority on the botany of citrus during his time period. The University of Miami’s Richter Library is the home to the Swingle Plant Anatomy reference collection. The collection consists of thousands of microscopic slides of citrus leaves, and stems. The university also holds Swingle’s personal papers in the archives and special collections of Richter Library.
Swingle also discovered dozens of new species and new genera of the citrus family. The Genus Swingelia was named in his honor. In 1941 he became consultant of tropical botany and head of the Swingle Plant Research Laboratory at the University of Miami. One of his most widely known works is The Botany of Citrus and its Wild Relatives of the Orange Subfamily (1943), which continues as one of the best references for citrus.