Christian Konrad Sprengel was a German naturalist, theologist, and teacher. He is most famous for his research on plant sexuality. Sprengel was the first to recognize that the function of flowers was to attract insects, and that nature favoured cross-pollination. Along with the work of Joseph Gottlieb Kölreuter he set the foundations for the modern study of floral biology and anthecology, but his work was not widely recognized until Charles Darwin examined and confirmed several of his observations almost 50 years later; see Fertilisation of Orchids (1862).