John Gerard, also spelt John Gerarde, (c. 1545–1612) was a botanist and herbalist.
 He maintained a large herbal garden in London.
 His chief notability is as the author of a large (1,484 pages) illustrated "Herball, or Generall Historie of Plantes".
 First published in 1597, it was the most widely circulated botany book in English in the 17th century.
 Except for the additions of a number of plants from his own garden and from North America, Gerard's "Herbal" is largely an unacknowledged English translation of Rembert Dodoens's herbal originally published in 1554, itself also highly popular (in Dutch, Latin, French and other English translations).
Critica Botanica ("Critique of botany", Leiden, July, 1737) was written by Swedish botanist, physician, zoologist and naturalist Carl Linnaeus (1707–1778).
 The book was published in Germany when Linnaeus was twenty-nine with a discursus by the botanist Johannes Browallius (1707–1755), bishop of Åbo.
 The first and only edition was published in July 1737 under the full title "Critica botanica in qua nomina plantarum generica, specifica & variantia examini subjiciuntur, selectoria confirmantur, indigna rejiciuntur; simulque doctrina circa denominationem plantarum traditur.
 Seu Fundamentorum botanicorum pars IV Accedit Johannis Browallii De necessitate historiae naturalis discursus".
Charles Frederick Millspaugh (1854–1923) was an American botanist, born at Ithaca, N.Y., and educated at Cornell and the New York Homeopathic Medical College.
 For several years he practiced medicine and from 1891 to 1893 taught botany at West Virginia University.
 In 1894 he was appointed curator of the department of botany of the Field Museum of Natural History; from 1897 to 1923 he was professor of medical botany at the Chicago Homeopathic Medical College.
 He was also lecturer on botany at the University of Chicago.
 Millspaugh carried on explorations in the West Indies, Brazil, and other parts of South America, and was the author of "American Medical Plants" (1887); "Flora of West Virginia" (1891); and many articles in scientific and popular journals.
The Society for Economic Botany is an international learned society covering the field of economic botany.
 It was established in 1959.
 Its official journal is "Economic Botany", published on their behalf by Springer Science+Business Media and the New York Botanical Garden Press.
 The society also publishes a biannual newsletter, "Plants and People".
 The president is Steven Casper (Cheverly, MD, United States).
 The society organizes annual meetings at different locations around the world, where it awards the prize of Distinguished Economic Botanist to particularly meritorious individuals.
Isaac Henry Burkill (18 May 1870 – 8 March 1965) was an English botanist who worked in India and in the Straits Settlements (present day Singapore).
 He worked primarily in economic botany but published extensively on plant biology, ethno-botany, insect-plant interactions and described several species.
 He published a two volume compilation on the plants of economic importance in the Malay Peninsula, collating local names and knowledge.
 He also wrote a detailed history of botany in India.
 The plant genera "Burkillia" and "Burkillianthus" were named in his honour.
Georg Heinrich Leopold Dippel (4 August 1827 – 4 March 1914) was a German botanist.
 He was the son of a royal Bavarian forester, Carl Friedrich Peter Dippel, and Sussanna Purpus.
 He attended schools is Kaiserslautern and Zweibrücken.
 From 1845, he studied at the Academy of Forestry in Aschaffenburg, until he graduated in 1848.
 During his time there he was a member of the Munich Corps Hubertia fraternity.
 He continued his studies in Jena under the tutelage of Matthias Jacob Schleiden.
 Under him, he learned more extensively about botany and pioneered his work in microscopy and his research on the structure of plant's bodies.
 From July 1869, he worked at the Technische Universität Darmstadt, as a Professor of Botany and Zoology, Botany, and Cellular Histology.
 His interests turned towards Dendrology at this point.
 He brought many foreign trees and shrubs, mostly collected by his first cousin Carl Albert Purpus in North America and Mexico, and sent them to Germany.
 He was the rector of the Technical University of Darmstadt from 1870–71 and the Dean of the Chemical-Technical School from 1882-87.
 He retired at the end of the summer semester in 1896.
Jacobus Theodorus (Jakob Dietrich), called Tabernaemontanus (1525 – August 1590) was a physician and an early botanist and herbalist, the "father of "German botany" whose illustrated "Neuwe Kreuterbuch" (1588) or "Eicones Plantarum" (Frankfurt, 1590) was the result of a lifetime's botanizing and medical practice.
 It provided unacknowledged material for John Gerard's better-known "Herball" (London, 1597) and was reprinted in Germany throughout the 17th century.
 His Latinized name represented a translation of his native town, Bergzabern (literally ‘mountain taverne’) in the Palatinate.
 Tabernaemontanus began as a student of the pioneer of Renaissance botany, Hieronymus Bock.
Historia Plantarum ("The History of Plants") is a botany book by John Ray, published in 1686.
William Roxburgh FRSE FRCPE FLS (3 or 29 June 1751 – 18 February 1815) was a Scottish surgeon and botanist who worked extensively in India, describing species and working on economic botany.
 He is known as the founding father of Indian botany.
 He published numerous works on Indian botany, illustrated by careful drawings made by Indian artists and accompanied by taxonomic descriptions of a large number of plant species.
 Apart from the numerous species that he named, many species were named in his honour by his collaborators.
David Allardice Webb or D. A. Webb (12 August 1912 – 26 September 1994) was an Irish botanist and chair of botany at Trinity College, Dublin from 1949 to 1966.
 He was son of George and Dr Ella Webb.
 In Ireland he had studied under Henry Horatio Dixon and also studied in the United Kingdom.
 In addition to botany he edited a history of Trinity College with R. B. McDowell and published a book on the history of art in Trinity College.
 In 1982 he received the Boyle Medal of the Royal Dublin Society.
 His botanical specialties included his work as a leading taxonomist of "Saxifraga".
 He died in a car accident on his way to the University of Reading's herbarium.
 The 8th edition of "An Irish Flora" was renamed "Webb's An Irish Flora" in his honour.

Question: Which botanist published the most popular botany book of his time?
Answer: John Gerard