WEEDS OF SPECIAL CROPS 51 



that would bring forth bountiful harvests." But no time 

 should be lost. Prof. Tourney says, in regard to condi- 

 tions in Arizona; "In the early days of our great West 

 almost the only method of travel from the Mississippi 

 Valley to our western coast and intervening points was 

 by caravan. Wagons drawn by horses and cattle were 

 several months in making the Journey. During this time 

 they subsisted almost entirely upon the natural forage 

 afforded by the country traversed. For the most part this 

 consisted of perennial grasses, which at that time were 

 everywhere abundant. The whole of the West was then 

 a great open pasture, unstocked save for the herds of buf- 

 falo, deer and antelope. Many regions which were then 

 covered with a luxuriant growth of grasses are now en- 

 tirely destitute of vegetation, if we exclude a few strag- 

 gling, stunted bushes and the yearly crop of annuals 

 which follow the summer rains. As a more specific case, 

 the rancher who drove the first herd into Tonto basin, in 

 central Arizona, found a well-pastured valley, every- 

 where covered with grass reaching to his horse's flanks. 

 In passing through this region a year ago, scarcely a 

 stalk of grass was to be seen from one end of the valley 

 to the other. The transformation has taken place in half 

 a score of years." 



As a result of the overstocking of pastures, weedy an- 

 nuals, like southern poverty grass, foxtail, squirrel-tail, 

 and awned brome grass, spring up and take the places 

 of the better perennial species, or the native ragweeds 

 and verbenas spread and occupy the soil. All of these 

 have become so plentiful that farmers remark on their 

 greater frequency of occurrence now than in former 

 years. Several rank growing weeds are abundant in 

 meadows and pastures of western Iowa. Sunflower and 

 marsh elder find in the rich alluvial soil of the river bot- 

 toms a most congenial place for development. They are 

 especially troublesome in land that is often flooded dur- 



