Peter Hamilton Raven is an American botanist and environmentalist, notable as the longtime director, now President Emeritus, of the Missouri Botanical Garden.
Arthur John Cronquist was an American biologist, botanist and a specialist on Compositae. He is considered one of the most influential botanists of the 20th century, largely due to his formulation of the Cronquist system as well as being the primary co-author to the Flora of the Pacific Northwest, still the most up to date flora for three northwest U.S. States to date. Two plant genera in the aster family have been named in his honor. These are Cronquistia, a possible synonym of Carphochaete, and Cronquistianthus, which is sometimes included as a group within Eupatorium. The former was applied by R.M. King and the latter by him and Harold E. Robinson.
Edgar Shannon Anderson was an American botanist. He introduced the term introgressive hybridization and his 1949 book of that title was an original and important contribution to botanical genetics. HIs work on the transfer and origin of adaptations through natural hybridization continues to be relevant.
Randall James Bayer is an American systematic botanist born in Buffalo, New York, who spent his childhood in East Aurora. He earned a B.Sc. with major in plant breeding and minor in horticulture in 1978 from Cornell University; an M.Sc. in systematic botany in 1980 from the Ohio State University; and a Ph.D. in 1984 from the Ohio State University with the dissertation Evolutionary Investigations in Antennaria. His interest in the genus Antennaria was inspired by noted evolutionary botanist George Ledyard Stebbins (1906–2000) who was a visiting professor at the Ohio State University in 1978–1979.
William James Beal was an American botanist. He was a pioneer in the development of hybrid corn and the founder of the W. J. Beal Botanical Garden.
Ihsan Ali Al-Shehbaz is an American botanist who works as adjunct professor at University of Missouri-St. Louis and Senior Curator at Missouri Botanical Garden. Al-Shehbaz's primary area of interest is Brassicaceae and The Durango Herald called him "a world expert on taxonomy of the family". A 2008 publication of the United States Fish and Wildlife Service called him "the world's authority on species in the genus Lesquerella". The author abbreviation "Al-Shehbaz" is attached to the numerous botanical taxa he has identified.
Rolla Milton Tryon Jr. was an American botanist who specialized in the systematics and evolution of ferns and other spore-dispersed plants (pteridology). His particular focus and interest lay in two areas, historical biogeography of ferns and the taxonomy of tropical American ferns.
George Neville Jones, usually known as G. Neville Jones, (1903–1970) was an English-born botanist who spent most of his life and career in the United States. He was a professor of botany at the University of Illinois (Urbana) at the time of his death.
George Hill Mathewson Lawrence was an American botanist, writer and professor of botany who helped establish the 'Liberty Hyde Bailey Hortorium', the Hunt Botanical Library and the Huntia journal. He was also an avid book collector, including books on the history of Rhode Island, historic books and botanical art.
Jesse More Greenman was an American botanist. He specialized in tropical flora, with emphasis on plants from Mexico and Central America. He was an authority on the genus Senecio and noted for his work at the Missouri Botanical Garden.
Pamela Soltis is an American botanist. She is a distinguished professor at the University of Florida, curator at the Florida Museum of Natural History, principal investigator of the Laboratory of Molecular Systematics and Evolutionary Genetics at the Florida Museum of Natural History, and founding director of the University of Florida Biodiversity Institute.
Aaron John Sharp, known professionally as Jack Sharp, was an American botanist and bryologist, considered an expert on mosses. The standard author abbreviation Sharp is used to indicate this person as the author when citing a botanical name.
Jan Salick is an American botanist who researches the interaction between humans and plants (ethnobotany) and conservation biology. Her specialisms include alpine environments, climate change, indigenous peoples and traditional knowledge. She is a past-president of the Society for Economic Botany and holds their Distinguished Economic Botanist award. She is also Fellow of the American Association for the Advancement of Science and received the Fairchild Medal for Plant Exploration. In 2019 she retired as Senior Curator of Ethnobotany at the Missouri Botanical Garden, and now has emerita status.
Brian Morey Boom is an American botanist who specializes in the flora of the Guianas and the Caribbean, the family Rubiaceae, ethnobotany, and economic botany.
John Cameron Semple is a botanist, cytotaxonomist, professor emeritus, and adjunct professor at the University of Waterloo in Ontario, Canada. He was born in Boston and earned a degree of Bachelor of Science in 1969 from Tufts University, followed in 1971 and 1972 by Master of Arts and Doctor of Philosophy degrees from Washington University in St. Louis. Semple is known for his work with members of the tribe Astereae, particularly goldenrods, American asters, and goldenasters, and he maintains the University of Waterloo Astereae Lab website. Semple's wife is Brenda, and in 2013, he named a newly discovered goldenrod species Solidago brendiae in honor of her.
Thomas Bernard Croat is an American botanist and plant collector, noteworthy as one of botanical history's "most prolific plant collectors". He has collected and described numerous species of plants, particularly in the family Araceae, in his career at the Missouri Botanical Garden.
Charles Bixler Heiser Jr. (1920–2010) was a professor of botany, known as a leading expert on the sunflower genus Helianthus. He is also noteworthy as the author of a "series of popular books that did much to promote botany to the general public."
Emanuel David "Rudy" Rudolph was a botanist, lichenologist, and historian of botany. He was "the first botanist to conduct diverse experiments on the total biology of lichens in both polar regions".
Ernest Jesse Palmer was a “collector-botanist” botanical taxonomist and plant collector. He began collecting in 1901, then collected professionally for the Missouri Botanical Garden starting in 1913 and for Harvard University's Arnold Arboretum from 1921, until 1948. He specialized in the genera Crataegus and Quercus.
Dr. Daniel Trembly MacDougal was an American botanist and writer. He is known for his work on desert ecology and as the earliest botanist to research Chlorophyll. He was the inventor of the MacDougal dendrograph, used to record changes in the volumes of tree trunks. He was a pioneer in studying the idea of Mutation Theory for controlling evolution. He helped to establish two botanical laboratories, the Desert Laboratory in Tucson, Arizona and the Coastal Laboratory in Carmel-by-the-Sea, California.
