宁夏盐池县草原常见植物同化枝解剖结构观察

ANATOMICAL OBSERVATION OF ASSIMILATINE BRANCHES OF SOME SPECIES IN YANCHI COUNTY, NINGXIA

According to the differences of assimilatine branches structure, thirty-three plant species in transitive region of steppe to desert steppe observed are divided into six types: normal, total-palisade, symmetry, ringpalisade, C_4 and reduced type. It is proved that different plants may adapt to the same environment in various way, which is expressed on their structures of assimilatine branches. The plants are typical mesophyte, typical xerophyte and intermediate between mesophyte and xerophyte. It is being proved that the course of the anatomical structures evolution from mesophyte to xerophyte is considered that: normal-total-palisade-symmetry-ring-palisade. The C_4 type is in a higher lever and the reduced is in a passive lever for adapting to their environment.