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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. [ABSTRACT FROM AUTHOR]

The Neotropical Region (NR) is one of the areas with the most plant diversity globally, and its richness of vascular epiphyte (VE) species is higher than Africa and Asia combined. This richness is a consequence of the heterogeneous climate and geological history of the region, both factors also being responsible for the plant distribution patterns. Here, we aimed to explore the phytogeographic relationships of the VE in the NR using 14,636 identified records from 173 surveys exclusively of VE, carried out in 14 countries and 23 biogeographic provinces, comprising 3849 identified species. We assessed the floristic patterns and relationships with climatic variables by multivariate analysis (cluster and ordination analyses). The clustering formed 13 main groups, partly corresponding to the biogeographic units of the NR. Our results demonstrate consistent floristic patterns confirmed through the analysis of floristic similarity, corroborating previous biogeographic classifications in well-studied areas, while broader patterns were found in poorly studied areas. We found a floristic gradient pattern, which allowed us to understand the relationships between environmental conditions and floristic patterns. Furthermore, we discuss our results under the light of the history that likely shaped the current distribution patterns and richness of the VE in the NR. The VE proved to be an important model for testing biogeographic classifications. We encourage the studies of this synusia in the several geographical gaps that remain in the NR, which undoubtedly will improve further studies and support conservationist policies. [ABSTRACT FROM AUTHOR]

Gentiana species and varieties in the Andes of South America are morphologically weakly differentiated and geographical distribution ranges are not known. Here, we recorded 20 morphological characters for 135 individuals of Gentiana from within and outside South America, and observed four additional characters from a large collection of georeferenced flower photographs. To assess geographical patterns and draw taxonomic consequences, the characters were evaluated individually using box plots and histograms, and together using multivariate ordination plots. Our data support the recognition of two species: one in northern South America, G. sedifolia Kunth, and one in southern South America, G. gayi Griseb., which seem to intergrade in southern Bolivia approximately where wet puna converges into dry puna vegetation. Unusually small individuals of the southern lineage occur in the very South (>45°S). We treat them as G. gayi subsp. magellanica (Kusn.) S.Pfanzelt et K.B.Hagen comb. et stat. nov. We found no support for other previously described species or varieties and if they exist they will be of local distribution only. The respective lectotypifications are made. In our preferred scenario, G. sedifolia and G. gayi have colonized South America independently from the northern hemisphere, although this was not unequivocal and both species are closely related. [ABSTRACT FROM AUTHOR]