Flower

The hunter-gatherer ancestors of modern humans surely noticed that flowers gave rise to fruits which could be eaten. Because flowers signaled an anticipated harvest, it has been suggested that these early humans instinctively considered flowers attractive, an instinct that modern humans may also have. Many modern cultures consider flowers attractive, and scholars have been fascinated with flowers for millennia.

Dioscorides, a Greek physician in Emperor Nero's army (first century A.D.), wrote the most influential early book on plants, De Materia Medica. This was the first book about the medicinal uses of plants, referred to as an herbal. Dioscorides's book had diagrams of many plants and their flowers, and this helped other physicians to identify the species of plant to prescribe to their patients for a particular ailment.

De Materia Medica remained an important reference on plants for more than 1,500 years. However, early scholars lacked the printing press, so all copies had to be scripted by hand. Over time, the pictures of plants and their flowers in these hand-copied herbals became more romanticized and less accurate.

The 1500s were the "golden age" of herbals, when European scholars published their own books whose illustrations were based on observations of living plants, rather than upon Dioscorides's diagrams and descriptions. With the invention of the movable type printing press, these herbals became the first published scholarly works in botany and were widely read.

Carolus Linnaeus of Sweden revolutionized botany in the mid-1700s. He classified plant species according to the morphology of their flowers and fruits. Modern botanists continue to rely upon flowers for identification as well as the determination of evolutionary relationships.

In Linnaeus's time, many people argued in the doctrine of "Divine Beneficence," which held that all things on Earth were created to please humans. Thus, people believed that flowers with beautiful colors and sweet smells were created by God to please humans. Christian Konrad Sprengel of Germany disputed this view in the late 1700s. He held that the characteristics of flowers are related to their method of reproduction. Sprengel published his theory of flowers in his book The Secret of Nature Revealed (1793).

Sprengel's ideas were not widely accepted in his own time. However, in 1841 the English botanist Robert Brown gave Charles Darwin a copy of Sprengel's book. This book influenced Darwin's development of his theory of evolution by natural selection, which culminated in the publication of The Origin of Species (1859). Sprengel's work also stimulated Darwin's subsequent study of orchids, and he wrote The Various Contrivances by Which Orchids Are Fertilized by Insects (1862). Dar win's important studies of flowers and pollination supported Sprengel's view that there is a relationship between the characteristics of a flower and its method of pollination. Moreover, Darwin demonstrated that some of the highly specialized characteristics of flowers had evolved by natural selection to facilitate their pollination.