Australian C₄ Grasses (Poaceae) - Leaf Blade Anatomical Features in Relation to C-4 Acid Decarboxylation Types

Abstract

Using fresh, preserved and herbarium material we have examined the leaf blade anatomy of the Australian C₄ grass flora (Poaceae) in relation to C₄ acid decarboxylation type (NADP-malic enzyme, NADP-ME; NAD-malic enzyme, NAD-ME; phosphoenolpyruvate carboxykinase, PCK). Our survey included almost all species of the subfamilies Arundinoideae and Chloridoideae and of the panicoid genus Panicum. We sampled all genera for the Panicoideae but for many only representative species were examined. Our data are cross-referenced with available anatomical and biochemical data on C₄ types, in particular with our own, which show a number of somewhat taxonomically predictable exceptions to established anatomical/biochemical correlations. We briefly consider C₄ types in relation to geographical distribution, pointing out that NAD-ME type species are poorly represented in agronomical research on the arid and semiarid zone, where many of these occur.