Abstract The Ceratozamia miqueliana species complex consists of six closely related species that exhibit similar gross morphology, but a wide range of leaflet shape from widely obovate in C. euryphyllidia and C. hondurensis to oblanceolate in C. zoquorum. However, despite the clear leaflet size variation, the taxon delimitation within the complex has been suggested to be uncertain when considering other traits, giving rise to doubts about the taxonomic validity of taxa, particularly of C. becerrae. Previous studies have shown that anatomical traits might be effective diagnostic characters to delimitate closely related cycad species. This study reviewed the anatomical variation of the Ceratozamia miqueliana species complex. We provide taxonomic treatment in the basis of anatomical trait variation. Although the six species occupy relatively mesic environments in tropical rainforest habitats, we found that some species exhibited leaflet anatomical traits associated to water stressed environments, suggesting historical adaptation to xeric conditions. The anatomical trait variation presented in this study agrees with a recent molecular phylogenetic study, clears up doubts on species relationships in the C. miqueliana complex, and validates the taxonomic recognition of C. becerrae.

中文翻译：

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基于小叶解剖特征分析的马齿苋（Zamiaceae）物种复合体的修订

摘要 Ceratozamia miqueliana 物种复合体由六个密切相关的物种组成，它们表现出相似的大体形态，但小叶形状范围很广，从 C. euryphyllidia 和 C. hondurensis 的广泛倒卵形到 C. zoquorum 的倒披针形。然而，尽管单张大小变化明显，但在考虑其他性状时，复合群内的分类群划分被认为是不确定的，这引起了对分类群，尤其是 C. becerrae 的分类有效性的怀疑。先前的研究表明，解剖特征可能是划定密切相关的苏铁物种的有效诊断特征。本研究回顾了 Ceratozamia miqueliana 物种复合体的解剖变异。我们在解剖学特征变异的基础上提供分类处理。尽管这六个物种在热带雨林栖息地中占据相对温和的环境，但我们发现一些物种表现出与水分胁迫环境相关的传单解剖特征，表明对干旱条件的历史适应。本研究中提出的解剖特征变异与最近的分子系统发育研究一致，消除了对 C. miqueliana 复合体中物种关系的怀疑，并验证了 C. becerrae 的分类学识别。