On the Greek island of Kos is a plane tree (Platanus orientalis) with an ancient history that has taken root throughout the world. It is called the Tree of Hippocrates, believed to be a descendent of the tree that provided a canopy under which the Father of Medicine taught his disciples in 5th century BC. Today, the ancient physician is regarded as a founder of modern medicine, and the plane tree has become a symbol of inquiry and ethics in medicine.
In the United States, it's a sycamore. Elsewhere, it's called a plane tree. But London has the only Traffic Light Tree. It is 26 feet tall, installed alongside two plane trees (Platanus × acerifolia), to replace one that was diseased, and died.