Leaf micromorphology in Poaceae subtribe Olyrinae (Bambusoideae) and its systematic implications

We analysed the leaf epidermal surfaces of 52 species of herbaceous bamboos belonging to all 20 genera of subtribe Olyrinae (Olyreae). We used scanning electron microscopy (SEM) and light microscopy (LM) to describe their foliar microcharacters and test the taxonomic utility of these characters in the subtribe. Shape and distribution of silica bodies, presence, type and distribution of papillae on the long cells and subsidiary cells and the presence and distribution of prickles and macrohairs were found to be taxonomically informative, whereas microhairs were not useful in this group. The type of papillae on the abaxial surface had a robust taxonomic value mainly at the generic level, whereas the distribution of these microstructures helped to differentiate some species of Arberella, Cryptochloa, Diandrolyra, Olyra, Piresia and Sucrea. We also confirmed that in some species, papillae associated with the stomata are on the long cells and project over the stomatal complexes, whereas in other species they occur on the subsidiary cells.