1. French sycamore is the bellflower family, bellflower genus of plants two ball bellflower alias, commonly known as "law". Two ball bellflower is a hybrid of the American sycamore. Root distribution is shallow, easy to victimize the typhoon and downward slant. Resistance to air pollution is strong, the leaves have the role of absorbing toxic gases and stagnant dust. This kind of tree trunk is tall, branches and leaves, rapid growth, easy to survive, resistant to pruning, so widely planted for avenue greening species, but also for fast-growing timber tree species; to Ryukyu dioxide, chlorine and other toxic gases have a strong resistance.

2.1640 in London, England, breeding, and then introduced by London to the world's major cities widely cultivated, used as street trees and garden trees. Modern bellflower was introduced to China in large quantities in the 20th century in the first and second generations, mainly planted by the French in the French Concession in Shanghai, so it is called "French sycamore", referred to as "Fatong", in fact, non-French origin, Hangzhou, commonly planted in the hybrid "Yingtong" the most. Two ball boll weevil has good hybrid advantage, fast growth, easy reproduction, leaf large shade, beautiful tree posture, pruning resistance, the role of air purification, known as "the world king of street trees".