Tepal surface micromorphology and its taxonomic implications in some species of Polygonaceae in Egypt

Tepal micromorphological characters of 15 species belonging to six genera of the tribe polygonoideae (Polygonaceae) in Egypt has been investigated using Scanning Electron Microscope (SEM) to assess the value and utility of the micromorphological topology of the tepals as an additional source of evidence in diagnosis and separation of Polygonaceae. The tepal surface have revealed some striking differences among the studied species. Four main patterns of sculpturing can be recognized viz. Favulariate, tuberculate, scalariform, and irregular reticulate. The cell surface is marked with striae, which exhibit various patterns of distribution. The microcharacters of tepals are discussed in relation to taxonomy and proved their significance in distinction between the studied taxa at the generic and specific levels. An identification key based on the tepal surface feature is provided.