"My Reputation is at Stake." Humboldt's Mountain Plant Geography in the Making (1803-1825)

Alexander von Humboldt's depictions of mountain vegetation are among the most iconic nineteenth century illustrations in the biological sciences. Here we analyse the contemporary context and empirical data for all these depictions, namely the Tableau physique des Andes (1803, 1807), the Geographiae plantarum lineamenta (1815), the Tableau physique des Îles Canaries (1817), and the Esquisse de la Géographie des plantes dans les Andes de Quito (1824/1825). We show that the Tableau physique des Andes does not reflect Humboldt and Bonpland's field data and presents a flawed depiction of plant occurrences and vertical succession of vegetation belts, arising from Humboldt's misreading of La Condamine's description (1751). Humboldt's 1815 depiction, by contrast, shows a distribution of high-vegetation belts that is consistent with La Condamine's description, while the 1824 depiction drops innovations made in 1815 and returns to simply showing numerous species' names, thus not applying Humboldt's own earlier zonation framework. Our analysis of contemporary reactions to Humboldt's TPA includes Francis Hall's posthumously published 1834 illustration of Andean plant zonation near Quito and Humboldt's reaction to Hall's critique. Throughout his work on plant geography, Humboldt disregarded some of his own observations, or confused them. At stake was his reputation as an innovator in the field of plant geography and a discoverer of the sequence of high-elevation vegetation belts on the world's mountains.