"in a long line one behind the other, stand the poplars"
Poplar Leaf
Creative Commons Attribution Share AlikePoplar Leaf - Credit: Willow
Poplar Tree
Public DomainPoplar Tree - Credit: Cherubino

There are 25-35 species of poplars in the world. The most common type is the aspen. They are medium-sized trees that grow 30-75 feet tall, depending upon the species.