views updated

Populus (aspens, cottonwoods, poplars; family Salicaceae) A genus of deciduous, dioecious, catkin-bearing trees, which differs from Salix in having many stamens in each male flower, toothed catkin scales, flowers with cup-like discs, and several outer scales to each bud. Populus tremula is aspen. There are 35 species, found mostly in the northern temperate zone. Many, including hybrids, are grown for timber.