Design of Sunflowers for Optimum Pollination

Everyone knows that sunflower heads turn to follow the Sun throughout the day, allowing them to get the maximum amount of sunlight. However, researchers have found another feature that helps sunflowers to thrive. Plant biologists at the University of California, Davis, have published a report showing the incredible design of sunflowers for optimum pollination.

The sunflower head has hundreds of tiny florets. The newest florets are at the center of the bloom, and the most mature are at the edges. Their design forms a distinctive spiral pattern from the center to the edge. Each floret blooms over two days. On the first day, the male part of the bloom opens, presenting pollen. The female stigma unfolds to receive the pollen on the second day. In some way, the florets coordinate their opening, beginning at the edge and moving toward the center. This progressive opening leaves a ring of female flowers outside the earlier stage of pollen-bearing males.

Pollinating insects (primarily bees) tend to land on the edges and walk toward the center. In that way, they pick up pollen after they have walked over the female florets. Then they carry the pollen to a different flower head for cross-pollination. This coordinated opening design attracts as many insects as possible and makes pollination as efficient as possible.

The sunflower’s circadian rhythm, influenced by sunlight, controls the opening of the sunflower’s florets. People, animals, and plants have a built-in circadian clock as part of our design. We see it in the design of sunflowers for optimum pollination.

Understanding how to develop plant cultivars that can optimize pollination is essential since the bee population has been declining. We have much to learn about God’s design in the plant and insect world. Studies like this can help us meet the food shortages affecting many people on this planet.

— John N. Clayton ©

References: the National Science Foundation and elifesciences.org