Data from: Disentangling species limits in the Vauquelinia corymbosa complex (Pyreae, Rosaceae)

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.

伞花瓦克木（Vauquelinia corymbosa）隶属于梨族（Pyreae）、蔷薇科（Rosaceae），是一种灌木状硬叶植物，主要局限分布于奇瓦瓦沙漠（Chihuahuan Desert），分布范围涵盖美国德克萨斯州、墨西哥科阿韦拉州，并沿东马德雷山脉（Sierra Madre Oriental）延伸至墨西哥伊达尔戈州（Hidalgo）。据此前的分类学修订研究，该类群包含6个亚种。伞花瓦克木存在显著的形态变异，尤以叶片性状为突出，且其多数亚种仅局限分布于该沙漠的特定区域。本研究基于从该6个亚种全分布区内的201份标本中采集的16个形态测量性状与4个解剖性状，开展了一系列单变量、多变量及系统发育分析，以明确该物种复合群中可被有效界定的物种数量。本研究同时分析了地理梯度下的形态空缺，以验证形态测量性状的差异空缺是否可有效区分物种，抑或此类差异仅为地理相关的变异所导致。各项分析结果一致认定，狭叶亚种（subsp. angustifolia）应被提升为独立物种，而其余亚种仍隶属于伞花瓦克木，其形态变异幅度显著。狭叶瓦克木（Vauquelinia angustifolia）具有典型鉴别性状：叶片极窄（中部宽0.4–0.6 cm，基部宽0.2–0.4 cm），叶柄较短（1–1.5 cm），且仅分布于奇瓦瓦沙漠东北部区域。