Plant Sexuality

Plant sexuality covers the wide variety of sexual reproduction systems found across the plant kingdom. This article describes morphological aspects of sexual reproduction of plants.

Among all living organisms, flowers, which are the reproductive units of angiosperms, are the most varied physically and show the greatest diversity in methods of reproduction of all biological systems. Carolus Linnaeus (1735 and 1753) proposed a system of classification of flowering plants based on plant structures; since plants employ many different morphological adaptations involving sexual reproduction, flowers played an important role in that classification system. Later on Christian Konrad Sprengel (1793) studied plant sexuality and called it the "revealed secret of nature" and for the first time it was understood that the pollination process involved both biotic and abiotic interactions (Charles Darwin's theories of natural selection utilized this work to promote his idea of evolution). Plants that are not flowering plants (green alga, mosses, liverworts, hornworts, ferns and gymnosperms such as conifers) also have complex interplays between morphological adaptation and environmental factors in their sexual reproduction. The breeding system, or how the sperm from one plant fertilizes the ovum of another, is the single most important determinant of the mating structure of nonclonal plant populations. The mating structure or morphology of the flower parts and their arrangement on the plant in turn controls the amount and distribution of genetic variation, a central element in the evolutionary process.