Badiands of Nebraska and South Dakota. 
Characters of environment. 
fe licallintty otesonl. 
. Loose and crumbling soil, “Buttes.” 
Bere and crumbling soil, ° 
Gy Dingait anc intense heat 
Characteristic plants 
asew : vermi ; 
Greasewood (Sarcobatus vermiculatus 
White sage (Eurotia lanta). 
A . 
Bunch grasses and herbs rare or occasional. 
Alkaline marshes and salt basins. 
Meadows here and there by sod grass (Distichlis 
spicata, stricta and Agropyron pseudorepens). 
Salty basins (Ruppia occidentalis and glasswort=Sali- 
COrmiagherbaced ). 
3. Saity soil near ponds. 
Sait bush (Atriplex, a chenopod). 
ereasewoods, adapt themselves to 
ily. 
2: 
4. These chenopods, 
wide range. 
XVI. DESERT PLANT SOCIETIES 
1. Factors of Environment in the Desert. 
The principal factors are: 
Ist, the very low rainfall. 
and, the great amount of evaporation. 
3rd, _ the alternation of rainy and dry seasons. 
Some of the minor factors are as follows: 
the strong light (solar radiation), due to the absence 
LSt, 
of clouds which form a blanket over the earth. 
and, high winds. 
3rd, the physical and chemical character of the soil. 
Salty or alkaline condition of the soil. 
Calcareous soils. 
The loose and crumbling condition of soil. 
The topography of the region. 
aR io) tor 0 
2. Characters of True Desert Plants. 
True desert plants, perennials, to preserve root and stem 
through dry period. 
1. Desert plants have to meet two general conditions. 
Ist, dry hot atmosphere; 2nd, dry soil. 
41 
