Abstract: The Leaf epidermis of Caragana microphylla Lam.,C. davazamcii Sancz. and C. korshinskii Kom that growing in the Inner Mongolia steppe were observed using light microscope (LM) and scanning electron microscope (SEM). Some index that is expressible as quantity was measured by analyses system of microphotograph. The results reveal that the epidermal cells on both adaxial and abaxial leaf surfaces are irregular or polygonal shapes,and their anticlinal walls are mainly straight-arched,scarcely sinuolate; The most epidermis cells are squamiform and have wax membane; Ornamentations of cuticular membrane are more striate. There are four types of stomatal aperture including anisocytic,anomocytic,paracytic and actinocytic distributed on epidermis,and the former two types are occupied mostly. Wax ornamentation has diverse patterns and covers the outer stomatal ledge (or rim). The inner margin of outer stomatal ledge (or rim) is smooth or sinuolate. These results suggested that the leaf epidermal micro-morphyological characters of C. microphylla,C. davazamcii and C. korshinskii are regulated by both the inherited and the environmental factors, most characters keep constant on genus level,whereas others which might offer the information to accessorial classification index are inconstant; The similarity of some morphological characters on ecological adaptive countermeasure were represented,whereas it is likely there is more conversant relationship between C. microphylla Lam and C. davazamcii Sancz. among the three species of Caragana.

Key words: Caragana plants, Micro-morphology of leaf epidermis, SEM, LM