The cottonwoods are three species of poplars in the section Aegiros of the genus Populus, native to North America, Europe and western Asia. Those in section Populus are large deciduous trees 20-45 m tall, distinguished by thick, deeply fissured bark, and triangular-based to diamond-shaped leaves, green on both sides (without the whitish wax on the undersides of balsam poplar leaves), and without any obvious balsam scent in spring. An important feature of the leaves's the petiole which's flatten… (More on Cottonwood)