The preference of certain plant species for gypsum soils with a patchy distribution leads to disjunct population structures that are thought to generate island-like dynamics potentially influencing biogeographic patterns at multiple evolutionary scales. Here, we study the evolutionary and biogeographic history of Nepeta hispanica, a western Mediterranean plant associated with gypsum soils and displaying a patchy distribution with populations very distant from each other. Three approaches were used: (a) interspecific phylogenetic analyses based on nuclear DNA sequences of the ITS region to unveil the relationships and times of divergence between N. hispanica and its closest relatives; (b) phylogeographic analyses using plastid DNA regions trnS-trnG and psbJ-petA to evaluate the degree of genetic isolation between populations of N. hispanica, their relationships and their genetic diversity; and (c) ecological niche modelling to evaluate historical distributional changes. Results reveal that N. hispanica belongs to an eastern Mediterranean and Asian (Irano-Turanian) clade diversified in arid environments since the Miocene-Pliocene. This species represents the only lineage of this clade that colonised the western Mediterranean, probably through the northern Mediterranean coast (southern Europe). Present Iberian populations display a high plastid genetic diversity and, even if geographically distant from each other, they are highly connected according to the distribution of plastid haplotypes and lineages. This can be explained by a scenario involving a complex history of back-and-forth colonisation events, facilitated by a relative stability of suitable conditions for the species across the western Mediterranean throughout the Quaternary.

某些植物物种对分布不均的石膏土壤的偏好导致了不连续的种群结构，这些结构被认为会产生岛状动态，可能会影响多个进化尺度的生物地理模式。在这里，我们研究了 Nepeta hispanica 的进化和生物地理历史，Nepeta hispanica是一种与石膏土壤相关的西地中海植物，显示出不规则分布，种群彼此相距非常远。使用了三种方法：（a）基于 ITS 区域的核 DNA 序列的种间系统发育分析，以揭示N. hispanica与其最近亲属之间的关系和分歧时间；(b) 使用质体 DNA 区域trn S- trn的系统地理学分析G 和psb J - pet A 评估N. hispanica种群之间的遗传隔离程度，它们的关系和遗传多样性; (c) 生态位模型以评估历史分布变化。结果表明N. hispanica属于自中新世-上新世以来在干旱环境中多样化的地中海东部和亚洲（伊朗-图兰）进化枝。这个物种代表了这个在西地中海殖民的进化枝的唯一血统，可能通过地中海北部海岸（南欧）。目前的伊比利亚种群显示出很高的质体遗传多样性，即使在地理上彼此相距遥远，它们也根据质体单倍型和谱系的分布高度连接。这可以通过涉及来回殖民事件的复杂历史的情景来解释，这得益于整个第四纪整个西地中海的物种适宜条件的相对稳定性。