The leaf anatomy of 15 taxa of Cyperus subg. Cyperus from Southern Brazil was analyzed aiming to find anatomic characteristics useful for identification. All the taxa studied have radiate chlorenchyma around the vascular bundles, Kranz anatomy of the Chlorocyperoid type and air cavities with starred cells in the diaphragms. The most important diagnostic characters are leaf-blade shape in cross section, arrangement and stratification of hypoderm and bulliform cells, degree of air-cavity development, and vascular-bundle arrangement. The results were useful to separate some exomorphologically similar species but were not conclusive for the definition of all specific or infra-specific complexes observed. On the other hand, the results reinforced the proposition of synonymies indicated by previous exomorphological analyses and micromorphological data of the fruit surface. The diagnostic value of the analyzed data is discussed and a comparative table is provided.
monocotyledons; morphoanatomy; C4 plants
