干旱区生态环境知识资源中心

Vauquelinia corymbosa (Pyreae, Rosaceae) is a shrubby sclerophyllous species largely restricted to the Chihuahuan Desert, distributed from Texas, Coahuila, and along the Sierra Madre Oriental to Hidalgo. According to a previous taxonomic revision, it comprises six subspecies. Vauquelinia corymbosa has noteworthy morphological variation, mostly in leaf characters, and the majority of its subspecies are restricted to certain areas of the desert. In this study, based on 16 morphometric characters and four anatomical characters collected from 201 specimens of the six subspecies throughout their distribution range, we ran a number of uni-, multivariate, and phylogenetic analyses to determine how many species can be recognized in this species complex. We also analyzed the gaps in morphology across geography to identify whether gaps in morphometric characters are indeed useful to separate species or if they are the result of variation related to geography. The results of the analyses coincided in recognizing that subsp. angustifolia should be considered a separate species and that the remaining subspecies are part of Vauquelinia corymbosa with remarkable morphological variation. Vauquelinia angustifolia has diagnostic characters such as very narrow leaves (0.4-0.6 cm at the middle and 0.2-0.4 cm at the base) and short petioles (1-1.5 cm) and it is restricted to the northeastern region of the Chihuahuan Desert.