By direct imaging, we evaluate the relative stiffness of a hexagonal columnar mesophase induced by the self-organization of amphiphilic columnar supramolecules, both quantitatively and qualitatively, based on examination of the planar texture, and of defects contained therein. Quantitative measurement was performed by an analysis of distortions around edge dislocations. The elastic anisotropy varies significantly with the degree of molecular association. The columnar supramolecule containing rigid tapered molecules is stiffer than weakly associated self-assembled macromolecules by an order, resulting in different stability of the mesophase. In addition, defect characteristics are examined to further understand these supramolecular assemblies and their elastic properties. Highly resolved +1/2 disclinations have been observed in the flexible columnar supramolecules. (C) 2002 American Institute of Physics.