Abstract: Anatomical type of leaves and cotyledons of 17 kinds of C₄ species from the genus Salsola (Chenopodiaceae) were observed. The results were as follows: there are two leaf anatomical types including Salsoloid with hypodermis (SALS+H) and Salsoloid without hypodermis (SALS-H), and four cotyledon anatomical types including C₃-dorsoventral mesophyll (C₃-DV), Atriplicoid with hypodermis (ATR+H), SALS+H and SALS-H. Anatomical types of leaf and cotyledon for the same species are not always consistent, which could be divided into two kinds. One is cotyledon and leaf have the C₄ anatomical structure, including leaf with SALS+H type/cotyledon with ATR+H type, leaf with SALS+H type/cotyledon with SALS+H type, and leaf with SALS-H type/cotyledon with SALS-H type. The other kind is leaf with C₄ anatomical structure, while cotyledon with C₃ anatomical type, including leaf with SALS+H type/cotyledon with C₃-DV type, and leaf with SALS-H type/cotyledon with C₃-DV type. Leaves and cotyledons of the species belonging to the same section of Salsola show regularity in a sense. For the species from the different sections, their anatomical types of leaves and cotyledons have some difference. And this difference has no direct relationship with their life forms and geographical distributions. To sum up, Chenopodiaceous Salsola belong to C₄ plants formed in the long-term evolution of various photosynthetic organs and anatomical structure, which makes them survive extreme arid environment such as high temperature, strong light and drought.

Key words: Salsola, leaf, cotyledon, anatomical type, C₄ plant, Xinjiang