24 RANGE IMPEOVEMENT IN ARIZONA. 



are nevertheless typical of large tracts of desert, not only in the Santa 

 Cruz, but in the San Pedro, Gila, and Salt River valleys as well. 



A triangular x3ortion of this reservation, consisting of 336 acres 

 adjoining the Southern Pacific right of way, has been placed under a 

 substantial four- wire fence supported on singed niesquite posts 13^ 

 feet apart. The area encompasses nearly all the varieties of exposure, 

 drainage, and soils, and is, in short, a tj^pical mesa region in everj^ 

 respect. The advantage taken of the railway fence enabled us to 

 inclose the tract at a minimum cost. Two miles of fence, at an approx- 

 imate cost of. 81 50 a mile, covers practically the entire expense of the 

 inclosure. 



When selected, this tract of land, like the surrounding region, fur- 

 nished practically no feed; the ground was bare, except for cacti and 

 shrubby growths of little or no forage value. On the higher and 

 poorer soils are found characteristic growths of the creosote bush 

 (Larrea mexicana)^ around the base of which is almost invariablj^ 

 found Perezia nana, which, unlike the vast majority of desert plants, 

 possesses a ver}^ pleasant odor. Scattered over the entire area are to be 

 found luxuriant growths of cacti, mainly of the genus Opuntia. The 

 main species of this familj^ are O. fulgida, O. spinosior, O. arbuscula, 

 O. engelmanni, Cereus fendleri, C. greggii, Ecliinocactus ivislizeni. 

 All of the lower areas have scattering growths of mesquite {Prosopis 

 velutina), palo verde {Parkinsonia torreyana), Zizyplius lycoides, 

 Lycuim sp., Riddellia cooperi, Bigelovia sp., and Eplidera trifurca. 

 A few specimens of Yucca elata are also to be found. These plants 

 formed the conspicuous portion of the vegetation in September, when 

 the land was selected, and there was no grass except an occasional 

 tuft of six- weeks' grass (Bouteloua aristidoides) and low grama {Bou- 

 teloua polijstachya). Soon after this date the tract assumed a more 

 promising aspect, and weed}' growths of various kinds began to spring 

 up after the very light summer rains. It was not until January, 

 however, that the vegetation became marked. From this time on 

 until the 1st of March there was an abundant development of short- 

 lived annuals. The most conspicuous of these was the California 

 popp3' {Eschsclioltzia mexicana), which was so abundant in localities 

 here and in other portions of the valley as to give its characteristic 

 golden hue to the entire landscape, sometimes for manj^ acres in 

 extent. The next in abundance was Indian wheat {Plantago fasti- 

 giata), of which a description will be found elsewhere (p. 15). 

 Besides these, there were a great many borages, which were often the 

 characteristic vegetation over large areas. The principal genera of 

 this familj^ represented were Pectocarya, Echidiocarya, Amsinkia, 

 Ecliinospermum, and Eretrichium. Among other conspicuous plants 

 may be mentioned Malacothix glabrata, Chceiiactis lanosa, Daucus 

 pusillus, Bowlesia sepientriolis, Erodium cicidarium, E. texanum, 

 Salvia columharic2, and the peculiar (Enotliera scapoidea. In a few 



