The Andes through time and the evolution and distribution of Andean floras

The Andes are the world’s most biodiverse mountain chain, encompassing a complex array of ecosystems from tropical rainforests to alpine habitats. Here, we provide a synthesis of Andean Tracheophyte plant diversity by estimating a list of all species with publicly available records, which we integrate with a phylogenetic dataset of 14,501 Neotropical plant species in 194 clades. We find that (i) the Andean flora comprises at least 28,691 georeferenced species documented to date, (ii) Northern Andean mid-elevation cloud forests are the most species-rich Andean ecosystems, (iii) the Andes are a key source and sink of Neotropical plant diversity, and (iv) the Andes, Amazonia and other Neotropical biomes have had a considerable amount of biotic interchange through time.