For finding valuable systematic characters, leaf epidermis of 77 taxa, representing 12 sections of the genus Clematis and three related genera in the Ranunculaceae, were examined mainly by means of light microscopy (LM), and partially by scanning electron microscopy (SEM). It was shown that the leaf epidermal cells were usually irregular or polygonal in shape. The patterns of anticlinal walls were straight, arched or undulate. The stomatal apparatus is anomocytic and exists in abaxial epidermis of all species, and in the adaxial epidermis of some species. Under SEM observation, the leaf epidermis was often striated, seldom nearly smooth, and often with flakes attached. Evidence from leaf epidermis serves as a criterion for distinguishing the subsections in sect. Meclatis(Spach)Tamura and in sect. Fruticella Tamura. The results also support that there are several separate evolutionary processes in the genus Clematis. Key words: Ranunculaceae; Clematis; leaf epidermis; stomatal apparatus
毛茛科铁线莲属的叶表皮特征及其系统学意义
史京华 李良千
（中国科学院植物研究所系统与进化植物学重点实验室，北京100093）
摘要： 用光学显微镜和扫描电镜,较全面地观察了铁线莲属(Clematis)植物和邻近类群的叶表皮特征,并对其系统学意义进行了讨论.在光学显微镜下,观察了铁线莲属12组63种5变种及其同族邻近类群3属9种;在扫描电镜下,观察了铁线莲属7组27种2变种及其邻近类群2属6种植物的成熟叶表皮细胞及气孔器的特征.在光学显微镜下可见:叶表皮细胞形状(表面观)为多边形、不规则形,垂周壁式样为较平直、浅波状和波状,气孔器普遍存在于下表皮,少数种的上表皮也有分布,其类型均为无规则型.在扫描电镜下可见:叶片通常具有条纹或有颗粒状或鳞片状附属物,气孔器外拱盖内缘通常为浅波状或近平滑.在黄花铁线莲组(sect. Meclatis (Spach) Tamura)和灌木铁线莲组(sect. Fruticella Tamura)中,叶表皮具有双面气孔器的特征对于组下亚组的划分有一定意义.并且叶表皮特征对于一些种的分类学处理也有一定的价值,同时也为属下组间的系统进化关系提供了一些线索.
关键词： 毛茛科；铁线莲属；叶表皮；气孔器
通讯作者。E-mail: <LqLi @ ns.ibcas.ac.cn.>。
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