Cronquist, Arthur

views updated


(b. San Jose, California, 19 March, 1919;

d. Provo, Utah, 22 March, 1992), botany, plant taxonomy, monography, phytogeography, systems of classification of flowering plants.

Cronquist provided the framework for ushering in a generation of plant systematists using phylogenetic analysis, molecular data, and bioinformatics. Best known for his system of classification of angiosperms (flowering plants), Cronquist should equally be credited for his body of work in floristics, the taxonomic study of the flora of a given geographic region. Two factors enabled Cronquist to become one of the foremost botanists in the twentieth century. The first was his ability to assimilate botanical information: Cronquist readily translated field observations and assessments of variation present in herbarium specimens into concisely written species descriptions and clear, usable, taxonomic keys. The second factor was Cronquist’s forty consecutive years at the New York Botanical Garden in the Bronx, New York, where he had access to a comprehensive herbarium and one of the best botanical libraries in the world. Cronquist would eventually incorporate his vast knowledge of angiosperm families gained from years of floristic studies into significant work focused on general systems of angiosperm classification.

Early Years . Arthur Cronquist was born in San Jose, California, and grew up near Portland, Oregon, and Pocatello, Idaho. Cronquist’s parents divorced when he was a young child, and he and his older sister were raised by his mother, Fern, who held a position with the Union Pacific Railroad in Pocatello. His involvement with the Boy Scouts of America played an important role in focusing his interest on the outdoors and prompting him to learn the natural history of the Pacific Northwest. Cronquist enrolled in the Southern Branch of the University of Idaho (later Idaho State University) in Pocatello and was influenced there by Professor Ray J. Davis, who was working on the Flora of Idaho. After completing a bachelor’s degree in 1938, Cronquist entered Utah Agricultural College (later Utah State University) at Logan and completed his master’s degree in 1940 under the direction of Dr. Bassett Maguire. The subject of Cronquist’s master’s thesis was the Aster foliaceous complex, and it marked the beginning of his lifelong interest in the Asteraceae (sunflower family). Because a childhood accident left Cronquist with incomplete use of his right arm, he was ineligible to serve in the armed forces in World War II and instead enrolled in a doctoral program at the University of Minnesota in Minneapolis. For his dissertation, directed by Dr. C. O. Rosendahl, Cronquist revised the genus Erigeron and strengthened his expertise in Asteraceae.

New York Botanical Garden . Focusing on a large family of flowering plants was instrumental in Cronquist securing a junior staff position at the New York Botanical Garden in 1943. Dr. Henry Gleason was completing The New Britton and Brown Illustrated Flora (3 vols., 1952) and drafted Cronquist to work on a treatment of Asteraceae for this work before Cronquist completed his dissertation in 1944. Cronquist then spent two years at the garden before teaching botany at the University of Georgia (1946–1948) at Athens and at State College of Washington in Pullman (later Washington State University) (1948–1951). It is no surprise that Cronquist elected not to remain a university botanist, because his true interests were centered on floristic work. Floristic treatments provide the tool required by the ecologist, forester, and members of the general public who need to know plant names and readily retrieve information regarding plants and include keys and descriptions used to identify plants in a given geographic region. A position at a botanical garden provided the flexibility of schedule needed to complete extensive field seasons as well as access to extensive herbarium and library holdings needed for floristic studies. After serving as a botanist with the Belgian government for a year, Cronquist rejoined the scientific staff at the New York Botanical Garden in 1952 and he remained there until 1992.

Cronquist’s return to the garden in 1952 rekindled his productive collaboration with Henry Gleason. Gleason’s New Britton and Brown Illustrated Flora, which contained Cronquist’s treatment of Asteraceae, appeared that year. Later, Gleason and Cronquist completed the Manual of Vascular Plants of Northeastern United States and Adjacent Canada (1963), known to a generation of plant taxonomy students as “the Green Bible.” In 1964 Gleason and Cronquist published The Natural Geography of Plants.

Gleason was the most influential individual in Cronquist’s career and immediately recognized his colleague’s gifts for synthesizing botanical information and reaching an audience outside his own discipline.

The link between systematic botanists and the general public is via published floras. Floras consist of keys to identify plants and descriptions of all species found in a particular region, and they also commonly include other pertinent information valuable to the general public such as ethnobotanical uses of plants, whether the plant is native or introduced, and notes on the ecological occurrence of species. Monographic and revisionary studies of taxonomic groups constituted the bulk of scientific work completed in systematic botany during the 1940s and 1950s. (Monographs provide a detailed analysis and synthesis of the existing taxonomic data for a family, tribe or genus of plants, plus additional results of the monographer’s original research of the taxonomic group.) These studies provided the framework for biosystematic studies in the 1960s, but the results of the monograph or revision are not readily available to the consumer of plant names. Cronquist completed revisionary studies but primarily as part of his preparations for floristic projects. Cronquist, who had summer jobs as a youth with the U.S. Forest Service in Idaho working on a range management project and was also an assistant to the Park Naturalist at Sequoia National Park in California, recognized that, too often, plant systematists produced works primarily for others in their own discipline. His return to the New York Botanical Garden propelled Cronquist into the position of being the foremost floristic botanist of his time, and besides his collaborations with Gleason, he contributed heavily to the Vascular Plants of the Pacific Northwest (1957–1969) and Intermountain Flora(1971–1992). Cronquist also excelled in instructing the next generation of floristic workers. His first doctoral student, Theodore Barkley, was a co-editor of Flora of the Great Plains (1986) and lead editor of the three Asteraceae volumes for the Flora of North America (2006).

Work on Classification . Cronquist expanded his interests to include general systems of classification and began publishing on the subject in 1957. His The Evolution and Classification of Flowering Plants(1968; 2nd ed.,1988) represents his views and approaches for understanding the relationships among flowering plants. In 1981 Cronquist’s An Integrated System of Classification of Flowering Plants, a detailed classification of plant families, was presented to the botanical community. His system was incorporated into both the Flora of North America and Flora of Australia(1982–). The views presented in An Integrated System were very much shaped by Cronquist’s warm working relationships with Armen Takhtajan of Russia, Robert F. Thorne of the United States, and Rolf Dahlgren of Sweden.

Many plant systematists refer to the relationships outlined in An Integrated System as the Cronquist-Takhtajan system, since the men so strongly collaborated with one another. Cronquist’s ability to synthesize information and write with ease placed him in the position to publish a thorough summary of the state of plant classification. However, a case could be made that Dahlgren could have also contributed a significant future volume on the subject had it not been for his untimely death in an auto accident. Cronquist’s An Integrated System provided the model classification that the present generation of plant systematists test, using phylogenetic analysis of molecular data.

Cronquist also used his considerable skills as a writer to reach a generation of general botany students. Introductory Botany, published in 1961 (2nd ed., 1971), was tailored for use in a two-semester course, and Basic Botany, published in 1973 (2nd ed., 1982), was widely adopted for use in one-semester courses. In both texts Cronquist framed the details of plant structure, function, and diversity within the context of organic evolution.

During his career, Cronquist was consulted on a number of legal cases, including a legal battle to prevent land development near Jackson Hole, Wyoming, and at least one creationism case. He also provided testimonies and statements regarding the taxonomy of Cannabis for several criminal cases involving the prosecution of individuals for possession of marijuana. Cronquist corresponded with Ernest Small, a Canadian colleague and expert of hemp use, on Cannabis taxonomy and its legal dimensions in American society.

Awards and Honors . Cronquist was active in numerous professional societies until his death. Many a presenter at professional meetings would shudder when Cronquist was in attendance. He often would ask questions in his distinctive, booming voice during presentations instead of waiting for the presenter to finish. After the presentation, Cronquist often chatted with his “target” and displayed his considerable warmth and charm as well as his full two meter (six-foot, eight-inch) stature. Throughout his career Cronquist was a guiding force for the American Society of Plant Taxonomists (ASPT), attending his last ASPT meeting in San Antonio, Texas, in 1991. Cronquist was the president of ASPT in 1962 and was second recipient of the Asa Gray Award, ASPT’s highest honor, in 1985. Cronquist was also president of the Botanical Society of America (1973) and the Torrey Botanical Club (1976). Other professional awards and honors bestowed upon Cronquist include the Leidy Medal of the Academy of Natural Sciences, in Philadelphia (1970), honorary vice president of the XII International Botanical Congress, held in Leningrad (1975), and the Medal for Botany of the Linnean Society of London (1986). Probably the greatest reward Cronquist ever received was a lifetime of pursuing his boyhood passions of plants and natural history. Arthur Cronquist died peacefully of heart failure while examining specimens of Mentzelia in the Brigham Young University herbarium.


The Arthur Cronquist Collection housed in the Records of the Herbarium of the New York Botanical Garden in The Bronx, New York, consists of correspondence, manuscripts and typescripts, research papers, institutional and legal records, photographs, and artwork spanning Cronquist’s activities at the New York Botanical Garden from 1942 to 1992. The full scope of Cronquist-related materials at the Botanical Garden can be found at Theodore Barkley, “Arthur Cronquist (1919–1992),” Taxon 42 (1993): 480–488, includes a complete list of Arthur Cronquist’s publications.


With C. Leo Hitchcock, Marion Ownbey, and J. W. Thompson. Vascular Plants of the Pacific Northwest. Seattle, WA: University of Washington Press, 1957–1969.

With Henry A. Gleason. Manual of Vascular Plants of Northeastern United States and Adjacent Canada. Princeton, NJ: Van Nostrand, 1963.

With Henry A. Gleason. The Natural Geography of Plants. New York: Columbia University, 1964.

Introductory Botany. 2nd ed. New York: Harper and Row, 1971.

With Arthur H. Holmgren, Noel H. Holmgren, and James L. Reveal. Intermountain Flora: Vascular Plants of the Intermountain West, U.S.A. New York: Hafner Publishing, 1971–1992.

An Integrated System of Classification of Flowering Plants. New York: Columbia University Press, 1981.

Basic Botany. 2nd ed. New York: Harper and Row, 1982.

The Evolution and Classification of Flowering Plants. 2nd ed. Bronx, NY: New York Botanical Garden, 1988.


Barkley, Theodore. “Arthur Cronquist (1919–1992).” Taxon 42(1993): 480–488.

“In Memoriam: Arthur Cronquist: an Appreciation.” Bulletin of the Torrey Botanical Club 119 (1992): 458–463.

Takhtajan, Armen L. “In memory of Arthur Cronquist (1919-1992).” Brittonia 48 (1996): 376–378.

Melanie DeVore