Sem study of cell walls of 24 desmids (desmidiaceae,chlorophyta) from China

Surface ornamentations of the cell walls of 24 desmid species varieties and forms belonging to 7 genera were studied under a scanning electron microscope (SEM). Among these desmids, 1 species and 1 variety are new to science, 13 species, varieties and forms are recorded in China for the first time. These desmids are subdivided into homogeneous and heterogeneous types based on the characteristic ornamentations on their cell walls. A unique ornamentation pattern, the centre of each scrobiculation with a small punctum regularly arranged on the cell wall, and very fine puncta scattered on the cell wall can only be revealed under high SEM magnification.