Who needs a watch to tell time when we got flowers?

Many species of flowering plants open and close their flowers at specific times throughout the day. The first person to make a recorded observation of this phenomenon was Androsthenes, an admiral of Alexander the Great, who noticed that a tropical Tamarind tree raise their leaves during the day and droop them down during the night. Many people made similar observations—Pliny the Elder, in the first century, and Albertus Magnus, the thirteenth century German bishop.