The Swedish botanist Carolus Linnaeus designed the flower clock

In the 18th century, Swedish botanist Carolus Linnaeus designed the flower clock, a timepiece made of flowering plants
that bloom and close at specific times of day. Linnaeus's plan wasn't perfect, but the idea behind it was correct.
Flowers can indeed sense time, after a fashion. Mornings glories unfurl their petals like clockwork in the early morning.