>me oi th6M ipeciei have been included in former list- <>r pap 

 on the trees of Nebraska. 



I have also included a number of exotic or introduced ipecisi in 



my description- Some of these are very commonly planted in many 



parts of the itate and people are interested in then aa tin-; in our 



native trees. 



BOl la EB OF OUB N.M TV! 



A Btudj of the origin of the flora of ■ given area ia one of the 

 most interesting phases of plant geography for the amateur. Nebraska 



occupies a unique position with reference to fhe greal N • it h 



America. The eastern portion of the state lie- in the lower Missouri 

 \ alley where the tree growth is composed of broadleaved 9] ike th< 



III. Leaf Tips 



Acuminate 



Acute 



Obtuse 



Mueronate 



of eastern United States, while the western end of the state lies within 

 the floral influence of the Rocky Mountains and its forests of broadleaved 

 and coniferous trees which are quite different from those of the e;i 

 The trees of the east have migrated westward and the trees of the 

 Rocky Mountain region have come eastward, and we find that many 

 .-uch species reach the extreme outer limits of their natural distribution 

 in our state. 



The western yellow pine and the narrow-leaf cottonwood are very 

 common trees in the Rockies that have migrated eastward and h; 

 entered western and northern Nebraska. The greater number of our 

 native trees, on the other hand, have entered the state from the east 

 and south via the Missouri river and its tributaries from the eastern 

 forests especially as they are represented in the Ohio valley. The black 

 walnut of the east meets and mingles with the western yellow pine 

 from the west in northern Nebraska in the vicinity of Valentine. 



Many eastern species have barely entered our state on their journey 

 westward and are to be found only in the extreme southeastern corner. 

 This fact is notably illustrated by the oaks and the hickories other 

 species have come farther into the state where they have, in general, 

 followed the stream courses quite closely. Besides these trees tin 

 • many other species which occur in Iowa and Missouri which h. 

 not yet reached Nebraska. And, of course, there are many trees in 

 Ohio and Kentucky which have not come as I tnd Mi 



ouri. 



