Abstract：
Hibiscus is a charismatic genus of the Malvaceae family that is noted for its diversity, lacking identifiable characteristics for distinguishing its various species. Therefore, there is an urgent need to develop authentication methods for genus delimitation and species delineation. The present study aims to discern the taxonomic relationships between the well-known, globally familiar, and economically important five Hibiscus species, namely: H. × rosa-sinensis, H. sabdariffa, H. schizopetalus, H. syriacus and H. tiliaceus based on traditional morphological and anatomical characteristics compared to the contemporary chemotaxonomy. In this context, the leaf-based methanolic extracts of the studied species were analyzed by Gas Chromatography-Mass Spectrometer (GC-MS) to estimate their secondary metabolites similarity. In addition, selected qualitative morphological and anatomical traits including leaf venation patterns, epidermal micromorphology, stomata types and trichomes diversity, petiole serial sectioning (outline, adaxial groove features, vasculature traces arrangement), and midrib characteristics of the studied species were investigated. The results of both chemotaxonomy and traditional taxonomy exhibited a remarkable agreement in the delineation of the five studied species. Specifically, the chemotaxonomy-based dendrogram separates the studied species into two main clusters with the H. sabdariffa as an outlier species in a single cluster and the remaining four species as another cluster with variant distances in its similarity indices. Similarly, the traditional morphological and anatomical characteristics revealed distinct traits for H. sabdariffa compared to the remaining four species. The findings of this study highlight the significance of integrating the structural features with phytochemicals profiling as a potential approach that could be harnessed for the delineation of the taxonomically challenging Hibiscus genus.
摘要：
芙蓉是锦葵科的一个有魅力的属，以其多样性而著称，缺乏区分其各种物种的可识别特征。因此,迫切需要开发属划界和种划定的鉴定方法。本研究旨在辨别众所周知的，全球熟悉，和经济上重要的五个木薯物种，即:红景天,H.sabdarifa,H.精神分裂症，与当代化学分类学相比，基于传统的形态学和解剖学特征。在这种情况下，通过气相色谱-质谱仪（GC-MS）分析了所研究物种的基于叶的甲醇提取物，以估计它们的次生代谢产物相似性。此外,选定的定性形态和解剖特征，包括叶脉模式，表皮微形态学，气孔类型和毛状体多样性，叶柄连续切片(轮廓，正面凹槽特征，脉管系统迹线排列)，并研究了所研究物种的中脉特征。化学分类学和传统分类学的结果在五个研究物种的描述中都表现出了显着的一致性。具体来说,基于化学分类学的树状图将研究的物种分为两个主要簇，其中H.sabdariffa作为一个簇的离群物种，其余四个物种作为另一个簇，其相似性指数具有不同的距离。同样，与其余四个物种相比，传统的形态和解剖特征揭示了H.sabdariffa的独特特征。这项研究的结果强调了将结构特征与植物化学物质分析相结合的重要性，这是一种潜在的方法，可以用于划分具有分类学挑战性的芙蓉属。
