2018 ASHS Annual Conference

Walter Tennyson Swingle grew up outside of Manhattan, Kansas, and was notorious in his passion for botany. Based on observations, he made up his own names for plants that were demonstrably different. His formal engagement with science was ignited when he discovered that plant names and taxonomic distinctions could be found in books! He attended classes at Kansas Agricultural College at 15, and when he graduated at 20 he had already published 27 scientific papers in plant pathology, plant breeding and genetics. Swingle joined the USDA in 1891, and in July was sent to Florida to investigate diseases in orange trees. He established a USDA laboratory and began a comprehensive program to breed disease- and frost-resistant citrus. He recognized the need for genetic diversity in crops and the risks of growing them in monocultures. He discovered some new species and several new genera: the genus Swinglea and several cultivars were named in his honor. In the citrus crosses he made or directed, he originated several new categories of citrus: the tangelos, citranges and citrumelos (now critical as rootstocks), and several other intergeneric hybrids. He conducted plant exploration, mainly in countries surrounding the Mediterranean, and introduced date palms, figs, table grapes, and ‘Clementine’ mandarins. He also brought in the Blastophaga wasp to pollinate Smyrna-type figs. In his duties in the USDA section of Seed and Plant Introduction, he received over 2000 plant introductions, but hundreds of accessions in GRIN list Swingle as the collector. After his retirement from the USDA, Swingle moved to Miami in 1943. It was here he completed his treatise on the taxonomy of the citrus subfamily. “Even in his retirement, Swingle inspired a generation of students with his knowledge, curiosity of nature, and insights into plants. His simple advice to students was ‘Look and look, again and again,’ words still relevant today”.