VEGETATION OF THE PRAIRIE. gOl 



1048. Meadows. These meadow formations (see Pound & 

 Clements) are found usually along river courses and around 

 lakes, and are intermediate between the forest formations and 

 the prairie. They are characterized by long-stemmed grasses 

 which are "sod-formers" (Elymus canadensis, Stipa spartea, 



Fig. 5060. 



Belt of forest bordering a stream in southeastern Nebraska. (Bot. Dept., Univ. 

 Nebr.) 



Agropyron pseudorepens, etc.). Some of the bunch-grasses 

 occur as secondary grasses. 



1049. The sand-hills. The sand-hills in Nebraska represent 

 dunes which have become fixed and are approaching a stable 

 condition. The beard-grass (Andropogon scoparius), one of 

 the bunch-grasses, is the dominant species, and, because of the 

 severe dry conditions, makes an open formation, while on the 

 sand plains another beard-grass (Andropogon furcatus), also a 

 bunch-grass, is the dominant one, and the formation is closer, 

 though sometimes open. The sand-plains thus represent, as 

 we would expect, a transition from the true prairie areas to the 

 more xerophytic condition of the sand-hills. What are called 

 "blowouts" are formed by the wind where the sand-binding 

 plants have been uprooted. They are similar to the troughs or 

 gullies formed in other dune regions (see Chapter LIV). 



1050. Subordinate to the bunch-grasses in the sand-hills 

 are xerophytic shrubs, herbs, and other grasses. The sand-hills 

 vegetation may be looked on as edaphic formations in the prairie 



