3.0-1 



in 



o 



c 



1.0- 



PRECIPITATION 



100-1 



80 



^ 60 H 



c 



O 



Q.40 H 



20 - 



FLOWER STALK GROWTH 



T 

 14 



July 



28 



"T 

 II 



August 



25 



8 22 



September 



Chart 5. Growth curves as measured by height of flower stalks of (A) Bouteloua 

 filiformis, (B) Bouteloua rothrockii, and (C) Trichachne calif ornica in relation 

 to the distribution of rainfall during one summer on the Santa Rita Experi- 

 mental Range in Southern Arizona. (After Reynolds, H. G. (169A), "Managing 

 Grass-Shrub Cattle Ranges in the Southwest," Figure 5, U. S. Dept. Agric. 

 Handbook, No. 162, 1-40 (1959).) 



a large number of individual plants can be measured. The plants 

 measured in the field should be marked and numbered so that 

 measurements can be taken of the same ones each time. Stems 

 may also be cut at the ground level and taken to the laboratory 

 for more accurate measurements. 



Many interesting and important results have been gained by 



106 • THe ComMnvaimity 



