The leaf anatomy of Australian members of the genus Atriplex. I. Atriplex vesicaria Heward and A. nummularia Lindl.

Abstract

These two species are shown to have a closely similar leaf anatomy, and this is fully described with relevant notes on all the minor points of difference.

In discussion, the origin and development of the lamina are compared with other plant groups. The autecological significance of the vesicular hairs is also briefly considered from an anatomical point of view. Brief comments are made on the water-storage properties of the hypodermal layer. The widespread occurrence of the 'Kranz' type of assimilatory tissue (concentric to the xylem of the leaf veins) in the Australian species of Atriplex is noted. The need for further investigations on the thick-walled phloem elements and bundle sheath cells is stressed. A taxonomic significance is suggested for the peculiar ventral development of the midrib in both species.