Consideraciones taxonómicas de Yucca queretaroensis Piña (Agavaceae), una especie endémica del Semidesierto Queretano-Hidalguense

Yucca queretaroensis  is an endemic species of the semiarid zone of Queretaro, Guanajuato and Hidalgo, Mexico. Due to its small population size, restricted distribution and habitat specificity, it is considered rare. This species is listed in the Mexican Official Standard as subject to special protection. When  Y. queretaroensis  was described as new species, it was placed within series  Rupicolae , section Chaenocarpa . A subsequent treatment placed it in series  Gracilifoliae , section  Yucca . However, neither of these treatments considered phylogenetic information nor provided a full morphological description of the species. Our goals are to complement the original description of the species including the fruits and seeds; to elaborate a botanical illustration; to compile and discuss the taxonomic history of the species and propose its new taxonomic position, based on morphological and phylogenetic information. We propose to move  Y. queretaroensis  into series  Treculeanae , section  Yucca  (ex  Sarcocarpa ) sensu McKelvey.