Stability of the floral structure in Leguminosae with flag versus non-flag blossom

This work is dedicated to the problem of natural variability of flowers with different types of symmetry. We focus on a comparative study of floral merism in Leguminosae with mono- and polysymmetric flowers. With few exceptions, most of the analyzed species exhibit a certain level of variation. Generally, monosymmetric flowers appear more stable than polysymmetric; variability of monosymmetric flowers with three types of petals (flag blossom) is lower than in monosymmetric flowers with two types of petals. Adaxial structures are more constant than abaxial ones, and no fluctuations are found in gynoecium morphology in pentamerous and pentacyclic leguminous flowers. We discuss these phenomena in light of the existing concept of genetic control of floral symmetry