Rudolf Jakob Camerarius

Rudolf Jakob Camerarius (1665 to 1721), also called Camerer, was a German botanist and physician, chiefly remembered for realizing that flowers are the reproductive organs of plants. Born at Tubingen, he became professor of medicine and director of the botanical gardens there in 1687. His investigations on the reproductive organs of plants appeared in a letter, De sexu plantarum epistola, of 1694. Other botanists such as John Ray and Nehemiah Grew had observed that plants seemed to have sex in some form and guessed that pollen was the male fertilizing agent, but Camerarius did the experimental work. Studying the mulberry, he found that female plants kept away from male plants bore fruit without seeds, and Mercurialis and spinach behaved the same way. He also cut off the staminate flowers of the castor oil plant and of maize and saw that no seeds formed. His results drew immediate attention, and later workers extended them from monoecious to dioecious plants.