Different patterns of aerenchyma formation in two hygrophytic species of Paspalum (Poaceae) as response to flooding

Production of aerenchyma took place in both species within the cortical parenchyma of roots, rhizomes and culms, and the mesophyll of leaf sheaths, both in flooded and unflooded plants. Under flooding conditions PAS increased in both species, although the individual response of organs differed: whereas in P. modestum PAS increased primarily in substratum-fixed roots, in P. wrightii all organs produced additional aerenchyma uniformly. Contrasting responses are understood as adaptations to permanent and seasonal flooding, respectively.