21 - Origins of Flower Morphology

Abstract

This chapter examines that flowers are morphologically the most complicated parts of the plants. Instead of being single organs, such as leaves, roots, and stems, flowers are composite structures composed of a number of organs that form an ordered pattern. It is this complexity that makes flowers so aesthetically highly attractive. In an evolutionary context, floral structural elements may be defined as the result of key innovations, which are intriguing steps in the phylogeny of organisms. The common floral organs are: sepals, petals, stamens, and carpels. These organs are present in flowers in a certain number and arrangement. It is especially apt to call them elements or building blocks as each organ commonly occurs in more than one copy in each flower. Thus they are modules of the modular structural complexes, which are represented by the flowers. Flowers, in turn, commonly occur in small or large numbers on an individual plant. They form inflorescences. Thus, flowers are by themselves elements or modules of a higher order.