星星草Puccinellia tenuiflora（Turcz.）Scribn.et Merr.解剖研究

利用扫描电镜技术，研究了星星草Ｐｕｃｃｉｎｅｌｌｉａｔｅｎｕｉｆｌｏｒａ（Ｔｕｒｃｚ．）Ｓｃｒｉｂｎ．ｅｔＭｅｒｒ．的营养器官，发现其根、茎、叶各部器官的组织具有显著的旱生结构特征，即根的皮层细胞破裂，形成发达的通气组织￣［１］；茎的表皮细胞排列紧密，角质层很厚，维管束不成两轮排列，而星散分布于基本组织中，髓腔较小；叶的表皮具乳突状表皮毛，泡状细胞数目较少，且深陷。叶脉维管束鞘不为典型的Ｃ＿３植物结构，两层维管束鞘的细胞壁厚度相等，内层维管束鞘壁并不加厚，外层维管束鞘含叶绿体。这些特征都表明星星草受外界生态因素影响，而演化出各种各样的形态结构来适应所生长的客观生态环境￣［２］。

The Anatomical study of Puccinella tenuiflora(Turcz.)Scribn.et Merr.

The anatomy and structure of roots.Stems and leaves from Puccinellia tenuiflora(Turcz.)Scribn. et Merr. have been studied using scanning electron microscopy in this paper.The result showed that this plant is a kind of growing in drought. In the room the cells at the middle cortex tended to be disorganized to form extensive intercellular spaces which function as the aerenchyma.Its stem' s epidermic cells were arranged in an orderly manner.Vascular bundle at inner layer were bigger than that of at outer layer.The Vascular bundles were scattered within the parenchyma tissues. Besides the pith leaved less room for the pith carity.The leaf's vascular bundles of veins were less developed.Bundle sheath was composed of two layers of cells with similar thickness of cells walls. The cells at outer layer contained chloroplasts. Therefore, it seems reasonable to assume that the anatomic structure of a plant may undergo certain changes environment.