Specific ornamentation of orbicular walls and pollen grains, as exemplified by Acanthaceae

Abstract

For the first time in Acanthaceae a comparative study of orbicules forming stable, coherent orbicular walls and the respective pollen ornamentation was undertaken. A peculiar acetolysis resistant, often species specific orbicular wall is typical for many genera. In some cases the orbicular wall ornamentation resembles closely the pollen ornamentation, in others it differs to a variable degree. The presumed function of orbicular walls is discussed. © 2005 Taylor & Francis.