Poplars and aspens are all in the willow family and share some of their traits, like fast growth and weak wood. This makes people think of poplars as 'junk trees' because they often die or fall over, and their wood is not valuable. However, they are an important food for beavers and porcupines. Our four native species can be easily distinguished from each other by their leaf shapes. Largetooth aspen has large teeth on the edges of its leaves.