The western yellow pine and the narrow-leaf cottonwood are very common trees in the Rockies that have migrated eastward and have entered western and northern Ne.ska..Take a stroll around your town or a drive across the state and you may ask yourself these, and other, questions about the numerous types of trees you will see. There are hundreds tree species in Ne.ska and across the United States. The following Web sites are guides to tree identification..Resources: For further information about Trees of Ne.ska or Ne.ska forestry, contact the. Ne.ska When identifying these species, follow the key closely..Once sp.ly forests, the landscape of. Ne.ksa offered little to the early pioneers of the. Within the forests of Ne.ska are some giants. Ne.ska Native Trees A to Z. While there are a few plants species endangered or threatened in. Eastern Cottonwood, Populus deltoides. Eastern Cottonwood, Populus deltoides..