SO ENDS this first of two weekends on the theme of floral symmetry. Symmetry is a pervasive theme in nature, from the quantum to the biological. It is still not clear why symmetry is such a powerful force, so seemingly keenly essential. In the case of flowers, the pollinators could as easily, it seems, have been conditioned on asymmetric flowers. But as we see, plants go to complicated generic solutions to maintain precise symmetric control.