5 August 2021

Fleabane has a daily exercise regimen that responds to light.

At sunset Philadelphia fleabane (Erigeron philadelphicus) and daisy fleabane (Erigeron annuus) close their ray petals and bow their heads. In the morning they raise their heads and open their petals, ready for insect pollination.

The process is called nyctinasty and is controlled by their circadian clocks.

Learn more about their exercise program and how to identify daisy and Philadelphia fleabane in this vintage article: The Bane of Fleas.

(photos by Kate St. John)