German-born botanist and physician. George Engelmann emigrated to the American West when it was still a frontier land and set to work describing the country's plants and building up a herbarium, leading him to be considered, along with Asa Gray and John Torrey, one of the pre-eminent botanists of the United States in the 19th century. He also helped to found what is now the Missouri Botanical Gardens.

Georg Engelmann was born in Frankfurt-am-Main, the eldest of 13 children (later Anglicising his name to George). His father was a schoolteacher. He studied science and medicine in Berlin, Heidelberg and Würzburg, maintaining a strong interest in botany, evident in his doctoral thesis on plant abnormalities, De Antholysi Prodromus (he used the word antholysis to refer to the breakdown of normal development in flowers).

Engelmann initially came to North America in 1832 on behalf of family members who wanted to purchase some land for investment. After visiting the English botanist Thomas Nuttall in Philadelphia, he travelled alone on horseback exploring Missouri, Arkansas and Louisiana for most of 1833, searching for plants as well as looking for land. He then decided to settle and practise medicine in the then rather rough outpost of St Louis, a gateway to the American West for trappers, traders and settlers, returning briefly to Germany in 1840 to marry his cousin, Dorothea Horstmann. Back in St Louis Engelmann continued botanising, but was eager to discover more about the country further west, paying close attention to news of exploration, especially natural history findings, and was soon involved in supporting scientific expeditions. He was also a keen observer of weather patterns and helped the US Army Corps of Topographical Engineers in their survey of the eastern Great Plains with his methodical barometric observations.

While working with John Torrey on the Flora of North America, Asa Gray came across Engelmann's name on specimens sent from St Louis to the herbarium in Berlin (Engelmann sent nearly 8,000 specimens there in the first 12 years he lived in St Louis). Gray wrote to Engelmann, initiating a longstanding botanical alliance. Thus Engelmann began playing a central role in recruiting and outfitting plant collectors to contribute to the Flora, acting as Gray and Torrey's frontier representative. Some of his collectors went all the way down the Rio Grande into Mexico (F.A. Wislizenus, F.J. Lindheimer), as well as to the Rocky Mountains (August Fendler) and the little-known west. Asa Gray remarked that George Engelmann was the 'gatekeeper for all scientists going into the wilderness'. Moreover, Engelmann had developed into a prominent botanist himself, processing and describing incoming plant specimens and building an expertise in cacti and conifers. One of his most splendid works was the illustrated "Cactaceae of the Boundary", published in the 1859 Report on the United States and Mexican Boundary Survey. He also held a long-running interest in euphorbias and Vitis. Indeed, he is said to have saved the French wine industry in the 1870s by sending over New World vines resistant to a disease that was decimating Old World vineyards.

In all Engelmann published more than 100 botanical papers and described 600 new taxa, all the while running his successful medical practice. While his published work is considered thorough yet modest, in the light of his work as a physician, which he carried on until his death and included dealing with outbreaks of cholera in the 1840s, it is a considerable achievement.

In around 1850 Engelmann became acquainted with the wealthy St Louis businessman Henry Shaw, who was planning a botanic garden and had been recommended to consult Engelmann by William Hooker. The botanist persuaded Shaw that it should have a library and herbarium to be a place of scientific study and thus spent 1856 in Europe, seeking books and specimens for the garden as well as studying in herbaria. He purchased the Bernhardi Herbarium for Shaw, and on his death Engelmann's own collection of 97,000 specimens became part of the Shaw's Garden Herbarium, later the herbarium of the Missouri Botanical Garden. The collections were mainly from the American West and Mexico, but also South America and Asia. Plants from Engelmann's private garden were also transferred to the grounds of the Botanical Garden after his death, which came following ill health that began about the time of his wife's death in 1879. Engelmann was instrumental in establishing the St Louis Academy of Science, and was a member of the American Academy of Sciences and a foreign member of the Linnean Society of London. He is recognised as one of the first modern botanists in America and a foremost expert on the country's cacti. George and Dorothea Engelmann's son, George Julius Engelmann, became a noted gynaecologist.

Sources:
Anon, 1884, "George Engelmann", Bulletin of the Torrey Botanical Club, 11(4): 38-41
P. Rebert, 2004, "George Engelmann and the great age of cactus discovery", Cactus and Succulent Journal of the Cactus and Succulent Society of America, 76(6): 311-316
O. Reifschneider, 1964, Biographies of Nevada Botanists: 31
E.A. Shaw, 1986, "Changing Botany in North America: 1835-1860 The Role of George Engelmann", Annals of the Missouri Botanical Garden, 73(3): 508-519
O.H. Soule, 1970, "Dr George Engelmann: The First Man of Cacti and a Complete Scientist", Annals of the Missouri Botanical Garden, 57(2): 135-144
S.J. Wolf, 1988, "George Engelmann type specimens in the herbarium of the Missouri Botanical Garden", Annals of the Missouri Botanical Garden, 75(4): 1608-1636.