瓦松(Orostachys fimbriatus)的形态解剖学研究

利用光学显微镜及扫描电子显微镜，全面观察了一种传统的东方药草——瓦松的茎内部结构、气孔器类型、大小、气孔指数、角质膜纹饰等叶表皮特征及花粉形态和外壁超微结构，并将瓦松的上述结构与景天属植物进行了比较。研究结果表明：瓦松的茎与景天属植物的茎构造基本一致，均由表皮(一层)、皮层(数层)及维管柱三部分组成，但两者在皮层薄壁细胞腔的大小、异细胞含量及维管柱中木质部有无间隔等方面差异明显。叶表皮方面，两者在气孔器类型及分布等方面是一致的，区别在于表皮细胞形状及垂周壁式样、气孔凹陷的程度，以及瓦松的角质层纹饰为十分致密的细小块(片)状，而景天属植物为较典型的条网纹饰等。孢粉学方面，瓦松与景天属植物各项特征亦基本一致，如均为近球形—长球形花粉，角萌发孔，三孔沟明显，外壁2层互内、外层几乎等厚，不同之处在于花粉粒的大小及外壁厚度上。建议将一些差异显著的特征，如角质层纹饰等，作为景天科属、种划分的重要依据。综合瓦松的形态解剖学研究结果，我们认为在系统发育方面，瓦松比景天属植物进化。

ANATOMICAL STUDIES ON OROSTACHYS FIMBRIATUS FROM CRASSULACEAE

The stem structure, leaf epidermis structure and the pollen morphology of a traditional orien-tal medical herb Orostachys fimbriatus ( Crassulaceae) were examined in detail under light microscope and scanning electron microscope and compared with those of Sedum of the same family. According to our anatomical studies, the stems of Orostachys fimbriatus and Sedum spp. consisted of epidermis,cortex and primary vascular tissue. They differed mainly in the size of parenchyma cells, the amount of idio-blasts and the type of vascular bundles. On leaf epidermis, the two distinguished in the shape of surface celis, anticlinal wall and the ornamentation of cuticle while they shared the same type of stomata, aniso-cytic type. As far as pollen morphology was concerned, the two had much the same characteristics such as the pollen shape, angulaperturate, 3 - colporate and ornamentation type on the exine surface. But the size and the thickness of exine wall differed distinctly. Some marked differences are taxonomically useful for the identification of genera and division of family. At the end of the article , the author concludes that Orostachys is superior to Sedum spp. .