Swedish-born botanist recognised for his work on palms. Dahlgren emigrated to the United States when he was in his teens and studied at the universities of Minnesota, Cornell and Columbia. He married Jane Means in 1890 and at the turn of the 20th century began volunteering at the American Museum of Natural History, working mostly on exhibitions. In 1904 he was offered, and accepted, the position of curator in the museum's Department of Preparation and Installation, where he remained for five years. In 1909 the Field Museum in Chicago took him on as the first head of the Division of Modeling in the botany department, where he was responsible for many fine botanical exhibitions and for creating the Stanley Field Collection of Plant Models. As well as working on many fine exhibits for the Field Museum, Dahlgren prepared some first-rate biological exhibits on behalf of the U.S. Public Health Service for the 1916 San Diego Exposition. He progressed to become assistant (1911) and associate (1921) curator of economic botany, rising to a full curatorship in 1935 (in 1936 his title became Chief Curator of Botany). During this stage of his career he published numerous articles on economic plants; one of his final publications before his attention turned to palms was The Story of Food Plants (1940).

Dahlgren's first botanical collecting trip took place in 1909, to Jamaica, where he gathered material for models of tropical fruits. He went on to amass many specimens from British Guiana and Brazil, especially palm material, again for exhibition purposes. The work involved in organising the collections led him to publish an "Index of American Palms" in Fieldiana: Botany 1936. He subsequently decided to learn Spanish so he could publish a translation of the Travels of Ruiz, Pavon and Dombey in Peru and Chile (1777-1788) that he had found during his research. From the time of these two publications, the major focus of Dahlgren's research became field and taxonomic studies of palms, especially South American species. His most intensive work was devoted to the genus Copernicia, which first caught his eye while on the Carnauba Expedition of 1935. He was a fastidious collector and record maker, collecting at the same sites several times during the year to gather specimens at different stages. Because of this trait, he assembled a near comprehensive collection of his favourite palm genus. Working until the last, he died suddenly of a heart attack in 1961. The genus Dahlgrenia Steyermark is named after him.

Sources:
E.D. Kitzke, 1962, "Bror Eric Dahlgren", Principes, 6(3): 84-86.