Abstract: The leaf epidermal cell micromorphology of 15 species of Sect. Conostylae(Wolf) Yü et Li of Potentilla L. from 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 analyzed. The results show that there are stomatal apparatus on lower epidermal of all 15 studied species, but no stomatal apparatus on upper epidermal of a few species. The shapes of stomatal apparatus are long oval, oval, wide oval and nearly round. 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 characteristics of stomatal apparatus, stomatal index, wax ornamentation and trichomes are all obviously different among different species in genus Potentilla L. The leaf epidermal morphological characteristics could provide evidence to identify subgenus and species of Potentilla L..

Key words: Potentilla L.;Sect.Conostylae(Wolf) Yü, et Li;stomatal;epidermal cell;micromorphology