90 PHYSICAL GEOGRAPHY. 



56. Glaucous Willow (Salix discolor). Generally a shrub, but 

 on the Missouri bottoms and on Willow Creek, a tributary of the 

 Republican, sometimes becomes a small tree. Is widely spread 

 over the State. 



57. Long-headed Willow [S. rostraid). This generally a shrub, 

 but often reaches the dimensions of a tree on the Missouri bottoms, 

 and especially in the St. John's timber in Dakota County. Found 

 on the Niobrara, Republican and Loup. 



58. Black Willow (S. nigra). Abundant on the Missouri bot- 

 toms in a few localities. Largest trees occur in St. John's timber 

 in Dakota. It is also found on the Republican, on Willow Creek, 

 Nemaha, Elkhorn, Loup and Niobrara. 



59. Shining Willow (S. lucidd). Generally a shrub, but on the 

 islands of the Platte and low Missouri bottoms it often reaches the 

 size of a small tree. Found also on the Elkhorn, Republican, 

 Loup and Niobrara. 



60. Long Silver-leaved Willow. (S. longifolia var-argophylla). 

 Also generally a shrub, but is found of tree size in St. John's 

 timber, in Dakota County. It is also found on the Loup and 

 Southeastern Nebraska. 



61. American Aspen (Poftitlus tremuloides.) I found this species 

 within our western border, only during the last few years. On 

 Upper Republican, North Branch of Platte and Niobrara. 



62. Cottonwood [P. monitifera.) This is the most widely spread 

 and abundant tree in the State, being found, with few exceptions," 

 on our western and northern border, wherever trees grow at all. 

 It apparently does equally well on upland or bottom. It constitutes 

 extensive forests on some of the Missouri bottoms. Some trees in 

 the St. John's timber, in Dakota County, five feet in diameter at the 

 butt, were over three hundred years old, as that was the number of 

 rings that were counted on them. 



63. Angled Cottonwood (P. angulata.) Rare. Found only in 

 northeast Nebraska. 



64. Balsam Poplar [P. balsamifera.) Have found it only in 

 Cedar Countv, and on the Niobrara. 



65. Var. Candicans of the above have found only on the middle 

 Niobrara. 



66. Western Yellow Pine (Pintis ftondcrosa.) Canyons and low 

 bluffs in western Nebraska and on the Niobrara. 



67. Pinus flexilis. Rare. Fonnd a few growing northwest 

 and southwest of Sidney, and finer ones on the Niobrara. 



