Comparative anatomy of Myosoton aquaticum and Stellaria media and its systematic significance

To provide evidence insight into the phylogenetic position of the myosoton monch.,the anatomy of myosoton aquaticum and stellaria media were comparatively observed by light microscopy and scanning electron microscope (sem). the anatomy of m. aquaticum and st. media is that (1) root is composed of uniseriate epidermis,parenchyma cortex,endodermis,pericycle and central cylinder,and primary xylem of root is tetrarch. (2) stem epidermis is arranged in closeness and parallel,and has distinct shuttle-shape tuber. (3) leaf is dorsiventral mesophyll with palisade layer and spongy parenchyma. (4) anomocytic type of stomatas are found in the epidermis of the leaf,stem and sepal. (5) pollen is single and spheroidal. a number of germ pores are completely sunken,papillate and polypantoporate. (6) crassuliod type of seeds have simple papillae and no strophiole is observed. seed coat is rounded shape minute secondary sculpturing with an outer surface formed by foveolate epidermal walls. (7) from the globular floral primordium develop to complete bisexual flower,the process of floral initiation is nearly the same. the result supports that: the higher similarity in organ anatomy and floral ontogeny of m. aquaticum and st. media,justifies it is appropriate that myosoton aquaticum belongs to stellaria. © 2016,pakistan botanical society. all rights reserved.