Taxonomic revision of the Chilean Puya species (Puyoideae, Bromeliaceae), with special notes on the Puya alpestris-Puya berteroniana species complex

The Chilean Puya species (Puyoideae, Bromeliaceae) constitute an early diverging group within the genus and thus are key taxa for the understanding of the early evolution and biogeography of Puya. However, a modern taxonomic treatment including information from molecular phylogenetic studies is still lacking. Here, a taxonomic revision of the Chilean species of Puya is presented based on morphological, molecular, and biogeographic data. A re-evaluation of the widely applied concept of P. berteroniana led us to the conclusion that the type of P. berteroniana is of hybrid origin and is maintained as Puya x berteroniana. Our studies revealed that the name P. berteroniana has been widely misapplied to what in fact is the northern metapopulation of P. alpestris, which is here described as a new subspecies, Puya alpestris subsp. zoellneri, a member of subgenus Puya. A lectotype is designated for Puya copiapina and a neotype for P. chilensis. Altogether, six Puya species, two subspecies, four varieties and one hybrid taxon are recognized for the Chilean flora in this revision: P. alpestris subsp. alpestris and subsp. zoellneri; P. boliviensis; P. chilensis; P. gilmartiniae; P. coerulea var. coerulea, var. intermedia, var. monteroana, and var. violacea; P. venusta; and P. x berteroniana. A key is provided for their identification