40 RAMALEY: XEROPHYTIC GRASSLANDS AT 
18. Festuca Bunch Grass Association; montane; dominated by 
tall cespitose species of Festuca. 
19. Muhlenbergia-Danthonia Consociation (of the Derivative 
Dry Grassland Association of the Montane Zone). 




| Platieville # 
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- 2. Map of that part of Colorado readily studied botanically from the 
University of Colorado at Boulder and from the Mountain Laboratory at Tolland. 
Contour lines are shown for 5,000 ft., 6,000 ft., 8,500 ft., and 11,000 ft. The moun- 
tain front is at about 6,000 ft. 
THE Mixep Dry GRASSLAND TYPE 
The term ‘‘Mixed Dry Grassland,” as used by the writer, in- 
cludes all mountain grasslands of mixed character, growing gener- 
ally in coarse-grained soil. In the preceding synopsis the com- 
munities numbered from 8 to 12 inclusive belong here and also 
Nos. 1 and 19. Early stages of the Short Grass Association, No. 
13, are also of the Mixed Dry Grassland type. The Porcupine 
Grass Association, No. 16, when it occurs in montane situations 
may resemble ordinary montane dry grassland, and the Festuca 
Bunch Grass Association, No. 18, is, in places, not so very dif- 
ferent. Indeed, any of the grassland associations of the mountains 
may belong to this general type. 
While there is no difficulty in recognizing inceptive and deriv- 
ative stages of the various dry grasslands the species concerned 
