Christian Konrad Sprengel

A small monument designed after the frontispiece of Spengel's fundamental work can be seen in Berlin Botanical Gardens. It was erected by Adolf Engler in 1917 after the 100th anniversary of Sprengel's death.

Christian Konrad Sprengel (22 September 1750 – 7 April 1816) 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 favored 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).

Life Sprengel was born in Brandenburg an der Havel in the Margraviate of Brandenburg. He was the 15th and the last son of a preacher Ernst Victor Sprengel and his second wife Dorothea Gnadenreich Schaeffer (died 1778). Ernst Victor's father had been an organist and he himself was a choirmaster, teacher and later archdeacon. Christian Konrad was expected to continue the traditional profession, and he studied theology in Halle. In 1774, in Berlin, he became a teacher and in 1780 moved to Spandau to head the Great Lutheran Town School. His interest in plants began around the age of 30 when he was advised by his surgeon to spend time outdoors for the health of his eyes. The surgeon was Ernst Ludwig Heim, an amateur mycologist and botanist who also influenced Alexander von Humboldt.

Sprengel undertook the study of plants, collaborating with Carl Ludwig Willdenow on his work Florae Berolinensis Prodromus (1787). He then proceeded to specifically study the pollination of plants, especially the interaction between flowers and their insect visitors in what was later called pollination syndrome. From his considerable research Sprengel published his first work, (Berlin 1793), which established him as a founder of pollination ecology and floral biology as scientific disciplines. Together with Josef G. Köhlreuter, a predecessor, he is acknowledged as one of the two classic authors in this field. While conducting his research on plants, Sprengel appears to have neglected management of the school, which mainly served the rich and powerful. Sprengel was accused of mistreating some of the students. He was accused of punishing a mayor's son by making him stand in class and hitting him with a stick leading to injury. A nine-year-old son of a councillor was beaten up as were several other children. Sprengel was ultimately dismissed from service in 1784.

Sprengel subsequently lived on a pension and earnings from leading public outings on botanical field trips. He published a work on the usefulness of bees in 1811, suggesting that beehives be placed close to planted fields to enhance crop yield via bee pollination. Towards the end of his life, he returned to studying classical literature and published his last book on Roman Poets with his comments in 1815. He died on 7 April 1816 and is buried at the Invalidenfriedhof in Berlin. His gravesite is unmarked and no portrait of him is known to exist.

The secret of nature discovered in the structure and pollination of flowers

During Sprengel's time scholars of natural science (naturalists), including botanist Joseph Gottlieb Kölreuter, viewed insects as only accidental or incidental visitors to flowers. They were seen as thieves of nectar which was considered a fluid meant to nourish the growing seed. (It was believed that the flower was the place for the marriage of the male and female parts and that self-fertilization was the norm.) Fertilization was understood by Kolreuter; he referred to pollen as farina fecundens (the "fertilizing flour"). Both Kolreuter and Sprengel believed in intelligent creation and sought and used teleological explanations of phenomena. (Like John Ray, Sprengel believed that observing nature was a kind of church service of beholding what "the wise Creator of nature had produced".) Important modern successors like Paul Knuth, Fritz Knoll, and Hans Kugler were inspired by Sprengel and advanced the fields of pollination ecology and floral biology. After the second World War, their work was continued by Stefan Vogel, Knut Faegri, Leendert van der Pijl, Amots Dafni, and G. Ledyard Stebbins, as well as by Herbert Baker and Irene Baker.

James Edward Smith named a genus of Epacridaceae in Sprengel's honour as Sprengelia. Kurt Sprengel, Christian Konrad's nephew who also wrote a history of medicine, was nominated to the "Regensburgische Botanische Gesellschaft".