Abstract:The leaf epidermal cell micromorphology of 10 species and 4 variations from five different groups of Potentilla L.of Xinjiang were investigated under light microscope (LM) and scanning electron microscope (SEM).The type of epidermal hairs,the size and shape of epidermal cells,the distribution and type of stomatal apparatus were studied.The stomatal size,stomatal density,and stomatal index were measured and counted.The shape and the ornamentation of outer stomatal rim were described.The results showed that there were stomatal apparatus on lower epidermal of all the 10 studied species and 4 variations.The shapes of stomatal apparatus are oblong oval,oval,broadly oval and suborbicular.The stomatal apparatus of most species are short paracytic four-cell type,irregular four-cell type,irregular type,around type and radial type.The trichomes are needle-like hairs or ribbon pubescent hairs.The epidermal cells are polygonal to irregular.The characters of stomatal apparatus,stomatal index,wax ornamentation and trichomes are all obviously different among different species in genus Potentilla L.The leaf epidermal morphological characters could provide evidence to identify species,classify subgenus and study the systematic relationships of taxons of Potentilla L.