Leaf epidermal micromorphology of 14 species of Berberis from Shaanxi

The leaf epidermal micromorphology characteristics of 14 Berberis species from Shaanxi (samples were collected from the herbarium of Northwest A&F University) were observed under a light microscope. The results showed that the shapes of the epidermal cells were polygonal or irregular, with anticlinal walls straight and arched or undulate. There were different degrees of thickening in the stratum cuticula of the epidermis. All the 14 species were hypostomatic. The stomata were mainly anomocytic and the shapes of the stomatal apparatus were oval, long oval, or wide oval. These characteristics were related to their drought tolerance. The results of data analysis on the characteristics of the stomatal index, stomatal density, and ratio of stomatal length showed that the stomatal index of the 14 species of Berberis in Shaanxi was quite different, and can be used for identifying Berberis species. Stomatal density was obviously different among specific species, and can be used for identifying specific species in a small range.