An Illustrated Diagnostic Key to Species in the Venezuelan Clade of Espeletia (Asteraceae)

Abstract

An illustrated key is presented to species in the Venezuelan clade of Espeletia (Asteraceae), based on herbarium specimens, virtual herbaria, and fresh samples from field collections. The 54 Espeletia species in this clade are documented: (i) 48 entirely endemic to the Venezuelan Andes, (ii) 2 found as well in the Venezuelan Cordillera de la Costa, the eastern section of the Colombian Cordillera Oriental, and the Sierra Nevada de Santa Marta, and (iii) 4 endemic to the northern section of Colombian Cordillera Oriental and Sierra de Perija. Schematic representations of leaves of all species are provided, including important diagnostic characters such as length-to-width ratios, and the shape, density, or angles of secondary nerves. Additional diagnostic characters are also described or illustrated for some species, such as the type of indumentum on leaves, the structure of the inflorescence, the size of the capitulum, and the color of ray ligules. The key has been shown to allow identification of species using both herbarium samples and fresh material, and given the predominant use of vegetative characters it is also useful on some monocarpic rosette species that are frequently found in the vegetative stage.