16 



RANGE IMPROVEMENT IN ARIZONA. 



occurred in the higher areas, occupied principally by the creosote bush 

 {Larrea mexicana). 



Number of plat. 



Weight 



of dry 



material 



per acre. 



Number of plat. 



Weight 



of dry 



material 



per acre. 



Number of plat. 



Weight 



of dry 



material 



per acre. 



1 



Pounds. 

 1,184 

 16 

 1,160 

 1,139 

 2,347 

 1,079 



7 



Pounds. 



342 



76 



1,286 



1,036 



56 



3,087 



13 



Pounds. 



1.52 



388 

 2,466 



1.53 

 1,594 



300 



9 



8. 



14 



3 



9 





4 



10.. 



16 



5 



11 





6..-. . 



12 



18... 







By comparison with the diagram on jifige 22, it will be seen that 

 the smaller weights in the table indicate areas where the creosote bush 

 predominates. These average the smallest in quantity, varying from 

 16 to 2,466 pounds per acre. An average of these plats gives a yield 

 of 992 pounds or practically one-half ton per acre, or 166^ tons for the 

 entire 336 acres under fence. The value of this material for stock 

 food must be determined by actual feeding tests and chemical analysis. 

 This the Station is now planning to determine. It may be said, how- 

 ever, that Indian wheat forms a large part of the feed on the range 

 during late winter and spring, and that cattle pastured on it and 

 alfilaria, while not in as good condition as those fattened on the 

 ranges of the Northwest, were still in fair condition for the market. 



These plantains appear especially Avell suited to grow on the sandy 

 desert mesa, where winds and destructive floods are liable to carry 

 away the seed. The method of seed distribution is indeed unique 

 and one of the most interesting the writer has ever seen. As far as 

 observed there appears to be no special method for scattering the 

 seeds,, but when the capsule is ruptured they fall, being scattered only 

 by chance influences of vegetation and wind. Each seed is sur- 

 rounded by a hyaline mucilaginous covering which is ordinarily incon- 

 spicuous when the seed is dry. When the seeds scattered over the 

 surface of the ground are moistened, as by a shower of rain, this cov- 

 ering swells, becomes mucilaginous, and attaches itself temporarily 

 to particles of earth or to whatever it comes in contact with. After 

 becoming thoroughly moistened the seed gravitates to the bottom of 

 the mucilaginous covering and rests upon the supporting soil. Upon 

 the evaporation of the absorbed moisture the mucilage dries in such 

 a waj^ as to leave the seed in the bottom of a small pit in the ground. 

 This depression has usually a diameter about three times that of 

 the seed and a depth equal to or slightly greater than the distance 



the surface during the 



The abrading of 



between its flat surfaces 

 subsequent two to five months, during which the seeds lie dormant, 

 serves to effectually cover them, so that they are ready for germina- 

 tion ui)on the advent of the summer rains. Just what the mechanism is 



