Many years ago Charles Darwin conducted some experiments to determine whether red clover is self-fertile. This investigator found that when insects were excluded, red clover did not produce a single seed, while flowers exposed to insects produced an average of twenty-seven seeds per head. The experiments of Darwin and many of the older investigators who conducted experiments with red clover were faulty since they did not release the anthers from the keel.
Proceedings of the Iowa Academy of Science
©1917 Iowa Academy of Science, Inc.
Pammel, L. H. and Kenoyer, L. A.
"Some Additional Notes on Pollination of Red Clover,"
Proceedings of the Iowa Academy of Science, 24(1), 357-366.
Available at: https://scholarworks.uni.edu/pias/vol24/iss1/55