(b. Sauquoit, New York, 18 November 1810; d. Cambridge, Massachusetts, 30 January 1888)
Gray was the son of Moses Gray and Roxana Howard Gray, who had migrated from New England to upstate New York after the American Revolution. He began his education in local schools at Sauquoit and for a time attended an academy at nearby Clinton, New York. In 1825 he entered Fairfield Academy and after a year began attending medical lectures at Fairfield’s College of Physicians and Surgeons of the Western District of the State of New York. Here he came under the influence of a remarkable group of peripatetic medical teachers, including James Hadley, who introduced Gray to chemistry, mineralogy, and especially botany. He began to collect plants during his apprenticeship in Bridgewater, New York, where for a brief time after receiving his M.D. degree in 1831 he practiced medicine.
Already in touch with the leading botanist in the United States, John Torrey of New York, Gray abandoned the practice of medicine in 1832 and spent the next five years in a series of part-time teaching and library positions while increasingly concentrating on botany and making himself so useful to Torrey that he became a full collaborator on the Flora of North America. In 1836 he became a member of the scientific corps of the U.S. Exploring Expedition but, tired by the delays in its sailing, he resigned in 1838 to take a professorship at the newly organized University of Michigan. That position entailed Gray’s spending a year in Europe, ostensibly to buy a general collection of books for the library but also to make the acquaintance of botanists and to study specimens of American plants in English and Continental herbaria. After his return in 1839, he worked on the Flora of North America while waiting in vain for a call from the nearly bankrupt state of Michigan. In 1842 Gray accepted the Fisher professorship of natural history at Harvard University, with the understanding that he could confine his activities to botany and the botanic garden. This milestone in the specialization of natural history made him the only adequately supported professional botanist in the United States and provided the home setting, both physically and institutionally, for the rest of his life.
Gray taught an elementary course in botany and offered a slight amount of advanced work to students of Harvard College, and later the Lawrence Scientific School, for thirty years. In 1848 he married Jane Lathrop Loring, daughter of a Boston lawyer and member of the Harvard Corporation. After 1873 he retired from teaching but continued to live in the house in the botanic garden and to develop the herbarium which ultimately became the property of Harvard. The only real breaks in the routine of his life after 1848 were a series of journeys—to Europe in 1850–1851, 1855, 1868–1869, 1880–1881, and 1887. He collected in the southern Appalachians as a young man and after the completion of the transcontinental railroad was fond of excursions to California, the trans-Mississippi West, and Mexico. Within this framework he lived an active and disciplined life until his last illness, which began in November 1887.
Gray became the leading botanical taxonomist in America in the nineteenth century, not because he was uninterested in physiology or unaware of the major advances made possible by the development of the achromatic microscope, but, rather, because the American setting demanded priority for a program of classification on a continental scale to match the programs of European nations in all parts of the globe not served by local collectors. Torrey and Gray’s Flora of North America not only accomplished the shift from the Linnaean classification, still prevalent in America in the 1830’s, to a natural system modeled on that of A. L. de Jussieu and A. P. de Candolle but also established the practice of thoroughly basing the taxonomy of American plants on the type specimens, until that time largely in the hands of European herbaria. By 1843 the Flora had proceeded in the Candollean system, beginning with the Ranunculaceae, through the Compositae, some seventy-six orders. At that point duties at Harvard and the flood of botanical returns from American expansion both westward and overseas in the era of Manifest Destiny made further progress by Torrey and Gray impossible.
Their response to the embarrassment of riches was twofold. Both Gray and Torrey devoted much of their time for the next thirty years to elaborating in reports the plants of collections sent in from the explorations. Some of these publications were in government documents, e.g., the Reports of Pacific Railroad Surveys (1855–1857) and the “everlasting” volumes of the botany of the U.S. Exploring Expedition, which were still incomplete at the time of Torrey’s death in 1873. Other reports reflected Gray’s sponsorship of individual collectors, who accompanied boundary surveys in the West and military expeditions, e.g., Plantae Fendlerianae Novi-Mexicanae (1849), Plantae Wrightianae Texano-Neo-Mexicanae (1852, 1853), and “Diagnostic Characters of New Species of Phaenogamous Plants, Collected in Japan by Charles Wright, Botanist of the U. S. North Pacifica Exploring Expedition” (Memoirs of the American Academy of Arts and Sciences, 6 , 377–452). In most cases Gray personally elaborated the orders through Compositae and called on others for other groups. Among the most regular and able collaborators besides Torrey were George Engelmann (especially Coniferae and Cactaceae), William Starling Sullivant (mosses), and Moses Ashley Curtis (fungi).
Gray’s other strategy, forced on him by the incompleteness of the Flora and the competition of the textbook writer Alphonso Wood, was to modify his scholarly standards and to limit his range to the northeastern United States, thus producing for general use a manual which covered in one volume all the flowering plants and some of the lower plants as well. The Manual of the Botany of the Northern United States filled a need that the slower-moving Floracould not meet. It went through five editions in Gray’s lifetime and has continued to be used in successive editions to the present time. After 1873 Gray minimized his writing of reports in order to return to the Synoptical Flora of North America. Much of the progress he made on it in his later years involved reworking in the light of accumulated scholarship the families treated in Torrey and Gray, so that it remained incomplete at his death. In matters of nomenclature and taxonomy Gray dominated American botany as no one before or after him; and if in the 1880’s a younger generation was beginning to chafe at his authority his work still made an impressive contribution to the stream of science.
In 1851 Gray had lunch with Charles Darwin at Kew. By 1855 Gray’s correspondence with Joseph Dalton Hooker on the geographical distribution of plants so impressed Darwin that he initiated an exchange of letters directly with Gray. Questions from Darwin led Gray to analyze the American flora on the basis of his Manual in an important paper, “Statistics of the Flora of the Northern United States” (American Journal of Science, 22 [l856], 204–232; 23 , 62–84, 369–403). In 1857 Darwin let Gray in on the secret of the trend of his theory in a letter that became one of the bases of Darwin’s priority for the idea of the origin of species by natural selection over Alfred Russel Wallace in the joint publication by Darwin and Wallace in the Journal of the Linnean Society in 1858.
Using Darwin’s ideas and the collections of plants then coming to him from American expeditions to Japan, Gray explained species and genera of plants which appeared in eastern Asia and eastern North America not as separate creations but as descendants of a Tertiary circum-Boreal flora which had been pushed southward by the Pleistocene glaciation. This exercise in statistics led Gray to “admit that what are termed closely related species may in many cases be lineal descendants from a pristine stock, just as domestic races are.” Thus he reached agreement with Darwin’s main contention early in 1859, months before the publication of Origin of Species. Gray’s announcement was the occasion for a full-dress debate with Louis Agassiz, his Harvard colleague who had imported an idealistic philosophy of natural history into the United States and gained an immense popular following.
After the publication of Origin of Species Gray was one of the leading reviewers on either side of the Atlantic, insisting on a fair hearing for Darwin in America and serving as agent to secure royalties on the American edition for the author. Until the Civil War distracted Gray’s attention, he was through his letters a leading voice in the Darwin circle, urging with Charles Lyell an accommodating strategy in meeting religious objections. Darwin published Gray’s commentary from the Atlantic Monthly at his own expense as a separate pamphlet under the motto “Natural Selection Not Inconsistent With Natural Theology”, Eventually Darwin rejected the strategy suggested by Gray concerning theology and the assertion that natural selection had not damaged the argument from design. Yet Darwin’s later years were largely spent on research that involved plants, and Gray figured prominently in his work on the coiling of tendrils and insectivorous plants. Darwin’s The Different Forms of Flowers on Plants of the Same Species (1877) was dedicated to Gray “as a small tribute of respect and affection.”
After the Civil War, Gray occasionally wrote anonymous articles attacking the religious opponents of Darwin, on the one hand, and those who followed T. H. Huxley into agnosticism, on the other. A clergyman, George Frederick Wright, eventually saw that these occasional pieces had a single author who was putting forward a consistent reconciliation of Darwinism and theism. Therefore he assisted Gray in collecting his occasional essays into a book, Darwiniana (1876), which firmly coupled Gray’s name with the defense of Darwinism, Protestant Christianity, and the argument from design in nature. In 1881 Gray delivered a series of lectures at Yale Divinity School which were published as Natural Science and Religion. Their failure to cause a stir is a measure of the accommodation reached by that time between Darwinism and American Protestantism.
Without being a forceful lecturer or teacher, Gray nevertheless was a major force in scientific education in his day. His full line of textbooks shaped botanical education in the United States from the 1840’s into the twentieth century. If few of his Harvard undergraduate students became professional botanists, he trained informally and assisted a whole generation of frontier collectors and part-time specialists who formed the rank and file of the botanical profession until German-trained Ph.D.’s began to appear in considerable numbers in the 1870’s.
Gray was a more modest institution builder than his colleague Louis Agassiz, but in 1842 he had found Boston and Cambridge with few resources, and he left them a permanent center of botanical study in the Harvard Botanic Garden and the Gray Herbarium. In addition, when he retired from active teaching in 1873, Harvard engaged four men in his place, some of them—e.g., Charles Sprague Sargent— major institution builders themselves. While his relationship with Darwin marks the peak of Gray’s career, his importaint on the pursuit of botany in the United States is also pervasive and enduring.
I. Original Works. Gray’s published writings, some 780 titles, are listed in [Sereno Watson and G. L. Goodale], List of the Writings of Dr. Asa Gray, Chronologically Arranged, With an Index,” in American Journal of Science, 36 (1888), app., 3–67. The major published collections of his works are Scientific Papers of Asa Gray, Charles S. Sargent, ed., 2 vols. (Boston, 1889); The Letters of Asa Gray, Jane Loring Gray, ed., 2 vols. (Boston, 1893); and Darwiniana (New York, 1876), A. Hunter Dupree, ed. (Cambridge, Mass., 1963).
The major MS collection is preserved in the Harvard University Herbarium, the library of which contains Gray’s books, many of them annotated.
II. Secondary Literature. The recent full-scale biography is A. Hunter Dupree, Asa Gray 1810–1888 (Cambridge, Mass., 1959), which includes notes and bibliography. Also relevant is A. D. Rodgers III, American Botany, 1873–1892: Decades of Transition (Princeton, 1944).
A. Hunter Dupree
American Botanist 1810-1888
Asa Gray was the dominant force in botanical science in the United States throughout the mid-nineteenth century. He substantially advanced and influenced the study of North American flora and the dissemination of information about it. Gray's studies led to a reassessment of floristic plant geography in North America, and he was famous for the sheer volume of his knowledge and the way he used it to advance American botany. Gray won respect for American botany from abroad. Moreover, he played a critical role in the eventual acceptance of Darwin's theories in the United States.
Asa Gray was born in 1810 in Sauquoit Valley, New York, near Utica. As a youth he helped his father with farm and tannery work. He attended Fairfield Medical School, where he first became acquainted with basic botanical principles. Gray was awarded a medical degree in 1831, but then took a position as an instructor in chemistry, mineralogy, and botany in Utica, thus beginning his career in botany.
Gray corresponded with the famed botanist John Torrey (1796-1873), sending him specimens of local plants. In 1833 he joined Torrey in New York, first collecting plants for him, then as his assistant, and then shortly thereafter as his collaborator. Gray had a talent for investigation and scientific description, and even at this early stage of his career he was writing for publication. In 1835 he became curator and librarian at the Lyceum of Natural History in New York. He then accepted a position as botanist of the Wilkes Exploring Expedition, but various delays, coupled with his work on other projects, led to his resignation in 1837 before the expedition even began. Some time after the expedition, Gray was brought in to help publish its scientific results.
Gray began working with Torrey on a comprehensive flora of North America as early as 1835. This project eventually necessitated the study of American specimens located in European herbaria. Also at this time, Gray received a job offer as professor of botany and zoology at the not-yet-opened University of Michigan, and he was assigned the task of travelling to Europe to purchase books and equipment. He consequently went to Europe to study specimens and purchase resources, and while there he met prominent European scientists, including Charles Darwin (1809-1882). In 1839 Gray returned to the United States. Two volumes of the Flora of North America were published in 1838 and 1843; a third volume was never completed.
By 1842 the University of Michigan had still not yet opened, and so Gray accepted an invitation to become Fisher Professor of Natural History at Harvard University. In the course of his work and correspondence he built up a large herbarium and library, resources that enabled him to continue his botanical investigations and publications. Many specimens collected by others were given to Gray so that he could study, identify, and, if necessary, name them, publishing their descriptions and expanding botanical knowledge.
Gray published prolifically, including major studies such as the Manual of the Botany of the Northern United States (1848), the Genera Florae Americae Boreali-Orientalis Illustrata (1848-49), and various reports on botanical findings from expeditions and surveys. He also wrote a number of popular textbooks, held in high esteem by his peers and used widely in preparatory schools and colleges. These included Elements of Botany (1836), First Lessons in Botany and Vegetable Physiology (1857), and How Plants Grow (1858). He published two parts of a Synoptical Flora of North America before he died, and two more parts were published later by others.
The Flora of North America
Gray maintained an intense interest in the flora of North America throughout his career. This interest was fueled by various plant collection efforts, particularly in the American West, conducted as a result of mapping and surveying being done for the railroads and the geological surveys. Collectors also accompanied military expeditions, bringing back specimens from farther afield. Several new scientific institutions were formed, in part to accommodate the data and specimens being gathered.
Collectors brought new species to the attention of both Torrey and Gray, who influenced where plants were being collected and how the resulting information was processed and disseminated. Gray's extensive studies of collected specimens gave him an unparalleled working understanding of the North American landscape and the plants within it, including their distribution.
Evolution and Plant Geography
Gray also studied specimens collected from elsewhere, and he eventually demonstrated a direct relationship between certain Japanese and eastern North American plants. Many of the same species were found in both places but not elsewhere. Gray argued for a common ancestry for these species, reasoning that they must have grown all the way across the northern continent at some time in the distant past, and that glaciers during the ice ages wiped out large sections of growth, so that the now-separated plants developed different characteristics. In 1859, this work led to a reassessment of plant geography in North America.
Gray expressed these ideas to Darwin, who also shared his own ideas with Gray before publishing them in On the Origin of Species in the same year. Gray became an advocate for Darwin's theories in the United States, helping to move the American scientific establishment further away from Linnaean ideas and toward those of Darwin. He demonstrated to scientists abroad that botany in North America was now being pursued with a professionalism comparable to that found in Europe. Gray was also a factor in the enhancement of scientific infrastructure in the United States, building an herbarium and library, influencing expeditions, and advising museums. These developments would persuade American collectors to entrust specimens to American institutions rather than sending them abroad to the great herbaria of Europe. Botany in the United States came of age with the work of Asa Gray. Gray received many honors during his lifetime and was a member of numerous academies and scholarly societies in America and Europe. He died in Cambridge, Massachusetts, in 1888.
see also Flora; Herbaria; Taxonomist; Taxonomy; Taxonomy, History of; Torrey, John.
Charlotte A. Tancin
Dupree, A. H. Asa Gray, 1810-1888. Cambridge, MA: Belknap Press of Harvard University Press, 1959.
Ewan, J. A Short History of Botany in the United States. New York: Hafner PublishingCo., 1969.
Humphrey, H. B. Makers of North American Botany. New York: Ronald Press Co.,1961.
Isely, D. One Hundred and One Botanists. Ames, IA: Iowa State University Press, 1994.
Kastner, J. A Species of Eternity. New York: Alfred A. Knopf, 1977.
Reed, H. S. A Short History of the Plant Sciences. New York: Ronald Press Co., 1942.
Reveal, J. L. Gentle Conquest: The Botanical Discovery of North America. Washington, DC: Starwood Publishing Co., 1992.
Spongberg, S. A. A Reunion of Trees: The Discovery of Exotic Plants and Their Introduction into North American and European Landscapes. Cambridge, MA: Harvard University Press, 1990.
Asa Gray (1810-1888), American botanist, pioneered in the study of plant geography and made early attempts to reconcile Darwinian concepts of evolution with traditional religious beliefs.
During the 19th century botany in America emerged as a highly professional vocation involving collaboration among collectors and herbarium specialists. A new method of classification was coming into use early in Asa Gray's career—the so-called natural system, which aimed at classification on the basis of general similarities instead of by the old, Linnaean method of counting the male and female parts of a flower. The new system forced botanists to look more closely at the forms and structures of plants. They began to study the interrelations between plants and their environment and to inquire into their meaning. Gray's professional lifetime bridged these important developments, and he played a part in all of them.
Asa Gray was born at Sauquoit, N.Y., on Nov. 18, 1810. After attending medical courses he received his degree in 1831 and began practice as a country physician. But he had already developed an interest in botany and began to drift away from medicine. From 1832 to 1835 he taught science at a high school in Utica, N.Y., utilizing the summers to improve his botanical knowledge. In 1835 he moved to New York City to begin collaborating with John Torrey on Flora of North America (2 vols., 1838-1843), which firmly established the new natural system of classification in American botany. Publication of the first volume made Torrey and Gray the leading botanists of North America and brought them international attention.
After accepting the professorship of botany at the newly founded University of Michigan, Gray sailed for Europe in 1838 to purchase books for the university and to study the type specimens of American plants in various herbaria. The year-long trip not only prepared Gray for his later task of coordinating North American botany but also laid the foundation of his lifelong friendship with leading European botanists. However, because the opening of the university was delayed, Gray never assumed the professorship.
In 1842 Gray became professor of natural history at Harvard, a post he held until retiring in 1873. The first edition of his Botanical Text-Book (1843) was long a standard work that did much to unify the interpretation and application of technical terms in America. Gray never lost his early interest in popular instruction; he produced five other textbooks, all important in lower-school education.
While at Harvard, Gray became the unofficial but widely recognized coordinator of American botany, maintaining regular correspondence with prominent European botanists and receiving a constant supply of specimens from U.S. government exploring expeditions and correspondents in the West. He created the Harvard department of botany and made its herbarium and botanical garden the finest in America.
Distribution of Plants
Gray was a pioneer in the field of plant geography. In 1859 he published his most famous contribution to this field, a monograph on the botany of Japan and its relations to that of North America. He demonstrated that the similar flora in the two regions had originated in one center and had been dispersed as conditions permitted. (This material was used by Charles Darwin to support his theory of evolution.) To explain the migration of flora in this case, Gray suggested that past geological changes would have made it possible; he thus joined a dynamic theory of the earth with a theory of plant distribution. Relying greatly upon information supplied by James Dwight Dana, a Yale geologist, Gray showed that, on at least two occasions in the past, conditions existed that could have allowed continuity between the flora of the two regions.
Advocate and Critic of Darwin
On Sept. 5, 1857, Darwin wrote Gray the famous letter in which he first outlined his theory of the evolution of species by natural selection. Gray became Darwin's first American advocate and also one of his most searching critics. Although Gray accepted the main outlines of Darwin's theory, his insistence that evolution must be directed by some external force allowed him to preserve his own Presbyterian beliefs. After Gray's initial review of Darwin's Origin of Species in the American Journal of Science, of which he was a coeditor, Gray spent much of his life arguing on both a popular and a scientific level for the compatibility of evolutionary theory and religion. He also arranged for the first American edition of Origin of Species.
One of the original members of the National Academy of Sciences, Gray was president of both the American Academy of Arts and Sciences and the American Association for the Advancement of Science and was a regent of the Smithsonian Institution. He died at home in Cambridge, Mass., on Jan. 30, 1888. His wife, Jane Loring Gray, whom he had married in 1848, edited his autobiography and letters.
Gray's correspondence was edited by Jane Loring Gray, Letters of Asa Gray (2 vols., 1893). An excellent biography which includes an analysis of Gray's contributions to botany is A. Hunter Dupree, Asa Gray, 1810-1888 (1959). See also Andrew D. Rodgers, American Botany, 1873-1892: Decades of Transition (1914; repr. 1944), and Edward Lurie, Louis Agassiz: A Life in Science (1960). For the general scientific background see George H. Daniels, American Science in the Age of Jackson (1968).
Dupree, A. Hunter, Asa Gray, American botanist, friend of Darwin, Baltimore: Johns Hopkins University Press, 1988. □
Gray, Asa (1810-1888)
Asa Gray (1810-1888)
Childhood. Asa Gray was the oldest of eight children born to a prosperous farmer in Oneida County, New York. Gray acquired his early education at a country school nine miles from his home. At age fifteen he began college preparatory studies at the Fairfield Academy in Herkimer County, where he was first exposed to the natural sciences. He became interested in botany in particular during the winter of 1827–1828, when he happened to read an essay on the subject in an encyclopedia. His curiosity aroused, he purchased Amos Eaton’s Manual of Botany and studied it enthusiastically until, finally, spring arrived. On one of his first botanical excursions after the snows melted, in April 1828, he discovered a rare and previously unidentified plant.
Professional Scientist. Gray began a medical apprenticeship under the tutelage of Dr. John Trowbridge of Bridgewater, New York, in 1828. From 1829 to 1831 he also studied at the College of Physicians and Surgeons of the Western District. He received the doctor of medicine degree in 1831 and practiced medicine in Bridgewater for about a year. As his interest in botany grew, his desire to practice medicine dwindled. He soon joined that cadre of young men who formed the first generation of professional scientists in the United States. For the next eleven years he alternated between lecturing in preparatory schools and colleges to earn enough money to survive and going on botanical excursions in New Jersey and New York. During this time he became the friend and protége of John Torrey, then the leading botanist in the United States.
The Natural System. Gray followed the lead of his mentor in espousing a new “natural system” for the classification of plants, rejecting the “artificial” Linnaean system that had prevailed since the mid eighteenth century. The Linnaean system classified all plants based on their number and type of reproductive organs. The natural system, on the other hand, considered a variety of characteristics in establishing relationships between plants. Gray’s career contributed significantly to the demise of the Linnaean system in the United States and the acceptance of the natural system; in this sense he helped revolutionize the research and teaching of botany. His first book, The Elements of Botany, appeared in 1836. He collaborated with Torrey in producing the two-volume Flora of North America between 1838 and 1843. In 1842 Gray published his Botanical Text-book, which appeared in numerous editions and served as the standard textbook in botany for most of the nineteenth century. He also later published five books that greatly contributed to the growing popularity of botany as a hobby.
Research Emphasis. Although he supported the popularization of science in general and botany in particular, Gray was first and foremost a research scientist. At various times he served as an officer of the American Academy of Arts and Sciences, the National Academy of Sciences, and the American Association for the Advancement of Science. From 1874 until his death in 1888, he was a member of the board of regents of the Smithsonian Institution. He joined the faculty of Harvard University in 1842 as a professor of natural history and continued in that position for the rest of his life. In that forty-five-year period he made major contributions to scholarship and gained an international reputation through more than 350 articles, scholarly papers, and books.
Relationship with Darwin. In addition to being a renowned scientist, Gray was a devout Christian of the Presbyterian denomination. He experienced religious conversion through the influence of the Torreys in 1835. Nevertheless, Gray became one of Charles Darwin’s most important North American correspondents and supporters. Because of his openly avowed faith Gray’s support was quite important for Darwin’s cause and added a lively dimension to the greatest debate in the annals of nineteenth-century science.
A. Hunter Dupree, Asa Gray, 1810–1888 (Cambridge, Mass.: Belknap Press of Harvard University Press, 1959).
Asa Gray was one of the central figures in American botany in the nineteenth century. Through his writing, teaching, collection, and correspondence, he had a major influence on the study of plants in the United States. Born in New York, Gray earned a medical degree before going to work for the famed American botanist John Torrey in 1833. By 1843 Torrey and Gray had published two volumes of the Flora of North America. A planned third volume was never completed. During this time Gray traveled extensively in Europe, where he met with Charles Darwin. Gray later became an important proponent of Darwin's ideas in the United States. In 1842 Gray became a professor at Harvard University, founding an herbarium there that still bears his name. Gray worked at a time when the American West was being explored systematically, and through his correspondence with collectors he greatly influenced where and how plants were collected, and how the information gleaned was used and disseminated. His prolific writings from this period include Manual of Botany of the Northern United States, a highly popular textbook Elements of Botany, and the first half of Synoptical Flora of North America, which was completed by others after Gray died.
see also Torrey, John
Asa Gray, 1810–88, one of America's leading botanists and taxonomists, b. Oneida co., N.Y. As professor of natural history at Harvard from 1842, he was the teacher of many eminent botanists. Through his voluminous writings in periodicals and his well-known textbooks, he helped popularize the study of botany. With John Torrey he explored the W United States and helped to revise the taxonomic procedure of Linnaeus on the basis of a more natural classification. Gray's Manual of Botany was edited by M. L. Fernald (8th centennial ed. 1950); it is a standard reference work for the flora of the United States E of the Rocky Mts. He initiated the quarterly Gray Herbarium Card Index, listing all the vascular plants of the Western Hemisphere described since 1873. Among his many other writings, which are still highly valued, are Structural Botany (6th ed. 1879) and The Elements of Botany (1887).
See his letters (ed. by J. L. Gray, 1893, repr. 1973); biography by A. H. Dupree (1968).
American botanist who was the leading authority on the subject in the United States for four decades. Educated as a physician, Gray became the first professor of botany at Harvard University, where he also supervised the botanical garden and established the herbarium of dried plant specimens. He traveled widely on two continents but collected little himself, preferring to classify plants gathered by others, many of whom he trained. His classic Manual of Botany(1848) was often revised by his successors and remained in print long after his death. He was the foremost American advocate for Darwin's theory of evolution.