The aim of this study was to analyze leaf anatomy of selected taxa of the Briza Complex and also of a related genus, Erianthecium Parodi, to provide data for the taxonomy of the Complex, whose circumscription is being discussed. Middle portions of the second leaf below the inflorescence of 21 taxa of the Briza Complex and of Erianthecium bulbosum were collected, fixed and processed according to conventional methodology for light microscopy. All species present anatomical patterns typical of festucoid and C3 grasses. The results suggest that the characters of the abaxial surface of the epidermis such as presence/absence of cork cells and shape of silica bodies are useful for understanding the taxonomic relationships within the Briza Complex, distinguishing Eurasiatic species from American species. The same applies to several characters of the leaf blade in cross-section, e.g. blade shape, amount of sclerenchyma and structure of the mesophyll. On the other hand, in the American species of the "Briza Complex", the three groups obtained here do not agree with any previous proposal of generic or infrageneric taxonomic categories.
Briza Complex; Erianthecium bulbosum; Gramineae; leaf anatomy; Poeae
