PLATE XV 



Fig. I. — Contrast in the progress of tlie flower stalk production of mountain bunch- 

 grass on portion of range which has been completely closed to grazing for a period of 

 three successive years and on range which has been subject to continued early grazing. 

 Section of fence temporarily removed. Photographed on July 7, 1909, before grazing. 



Fig. 2. — Western porcupine grass (Stipa occidentalis) , showing empty glumes and 

 floret with the scale and its awned projection to the left; to the right the floret with 

 glumes removed, showing the sharp-pointed, slightly-curved seed tip. Natural size. 



Fig. 3. — Average development of the root system and aerial portion of mountain 

 bunch-grass at end of the first growing season. Natural size. 



