Bramwel, D., Moura, M., Neto, A. I., Santos-Guerra, A. & Francisco-Ortega, J. (2019) William Trelease and the Macaronesian flora: an introduction to his trips, works and collections. Vieraea, 46, 459-498.
William Trelease (1857-1945) was the first director of Missouri Botanical Garden and one of the most important botanists in the history of the United States. He visited the Azores (in 1894 and 1896), Madeira (in 1896), and the Canaries (in 1932). His expeditions to the two Portuguese archipelagos are well-known and resulted in: (1) a floristic monograph for the Azores (published by Trelease in 1897) and (2) taxonomic treatments for the native mosses of Madeira and the Azores [published by the French bryologist Jules Cardot (1860-1934) in 1897]. From his writings it seems that his two expeditions to the Azores were inspired by Darwin’s work and findings in the Galapagos Islands. His three month visit to the Canaries (Tenerife) did not yield any particular publication and has not been the subject of historical research. Based on documents and photos housed in the University of Illinois at UrbanaChampaign Archives we found details of the stay that William Trelease and his wife [Julia J. Trelease, (ca. 1860-?)] had in Tenerife between ca. January 27 and April 3, 1932. These documents show that dried plant specimens were shipped to the herbarium of University of Illinois at Urbana-Champaign (ILL). During his voyages to the Azores he interacted with two of the most important naturalists from these islands, Bruno Tavares Carreiro (1857-1911) and Francisco Afonso Chaves (1857-1926), with whom he exchanged correspondence. In contrast, it appears that during his stay in the Canaries, Trelease did not meet any natural history specialist from these islands.