Review of leaf anatomy and ultrastructure in the Chenopodiaceae (Caryophyllales)

Species of the group Caryophyllales have four carboxylation variants (C-3, C-4 NADME, C-4 NADPME and CAM) with the Chenopodiaceae having the first three of these, For this reason, species of the family Chenopodiaceae (order Caryophyllales) have been examined for studies on the carboxylation pathways (C-3 and C-4) The grasses are the only other group to show similar variation but with CAM absent and C-4 PCK present. In other groups as well as the Caryophyllales, the carboxylation variants are correlated with anatomical and ultrastructural characters. The distribution of the C4 carboxylation syndrome is examined in both the Chenopodiaceae and the Caryophyllales. The anatomical and ultrastructural variations associated with the carboxylation pathways in the Chenopodiaceae are described and examined in detail, Various proposed classifications of and within the family are examined in relation to the anatomical and ultrastructural characteristic,. It is concluded that while the characteristics of the various carboxylation pathways help in understanding some relationships, our current knowledge presents almost as many problems as answers.