Understanding the spatial and temporal evolution of biota in the tropical Andes is a major challenge, given the region's topographic complexity and high beta diversity. We used a network approach to find biogeographic regions (bioregions) based on high-resolution species distribution models for 151 endemic bird taxa. Then, we used dated molecular phylogenies of 14 genera to reconstruct the area history through a sequence of allopatric speciation processes. We identified 15 biogeographical regions and found 26 events of isolation and diversification within their boundaries that are independently confirmed with disjunct distributions of sister taxa. Furthermore, these events are spatially congruent with six geographical barriers related to warm and/or dry river valleys, discontinuities in elevation, and high peaks separating fauna from different range slopes. The most important barrier is the Marañon River Valley, which limits the boundaries of four bioregions and is congruent with eight phylogenetic distribution breaks, separating the Central and Northern Andes, where the most bioregions are found. We also show that many bioregions have diffuse and overlapping structures, with contact and transition zones that challenge previous conceptions of biogeographical regions as spatially simple in structure. This study found evidence that the drivers of our identified bioregions were processes of Andean uplift and mountain dispersal facilitated by temperature oscillations of the Pleistocene. Therefore, Andean bioregions were not formed from one simple biogeographical event in a certain time frame, but from a combination of vicariance and dispersal events, which occurred in different time periods.

Taxonomic treatments of Pilosocereus in the Andean and Caribbean regions have varied widely. Recent authors often recognized three species only (P. lanuginosus, P. polygonus, and P. royenii), while Britton & Rose in 1920 (sub Cephalocereus) recognized 18 species in the same region. A revision of Pilosocereus is necessary, and it was carried out by the study of both herbarium specimens and living plants. Twelve species of Pilosocereus are recognized in the present paper for the Andean and Caribbean regions, including one new combination, i.e. P. curtisii, and one new species, i.e. P. jamaicensis. Typifications are provided for several names, including the Linnaean basionym Cactus royenii. Morphological descriptions, distributions, and an identification key of the recognized species are provided.

abStract. A new species of Lepanthes from the Western Cordillera of the Colombian Andes, characterized by similar triangular sepals with a large and protruding column, is described and illustrated. The new species is similar to Lepanthes pelorostele from Ecuador, but can be distinguished from the latter by having orange and ciliate sepals and larger petals and lip.reSuMen. Se describe e ilustra una nueva especie de Lepanthes de la Cordillera Occidental de los Andes colombianos caracterizada por tener sépalos triangulares similares y una columna sobresaliente. Esta nueva especie es similar a Lepanthes pelorostele, de Ecuador, pero se puede distinguir de esta última por tener sépalos ciliados, anaranjados y pétalos y labelo más grandes.

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Two new species of Lepanthes from the Central Cordillera of the Colombian Andes are described  and illustrated. Both were found during a botanical expedition to Puracé National Natural Park, within the  high Andean forests ecosystem of the municipality of Puracé, in the department of Cauca. Key Words: Cauca, Colombian Massif, Kokonukos, Paletará, Puracé National Natural Park