TnK LARGE IXOLOSURK. 23 



rouh'ft at slij'-htly lower levels. Contined mainly to the loose sands in 

 the vicinity of the washes, hut also at times extending over portions 

 of the rocky hillsides, is a scatterinj^orowth of Boutelouavestifa., while 

 Muhlrnhnujia porter I ^ the l)la('k grama of this region, is invariably 

 limited to the protection of cat-elaw and other si)iny or thorny shrubs. 

 The I'ough grama {H<)}tteJoua /i/'r.-n/fi/) is usually found upon all of the 

 rocky banks, but it is at home in the higher blutl's and mountains 

 bevond the inclosure. The same may be said of the side-oat grama 

 {/ioxtehna CHrtlpendala). Growing under the protection of ])ushes 

 along the arroyos in this section is always to be found more or less 

 Pan! cum laclinanthum. 



In the spring these open, grassy foothills are a veritable flower 

 garden of magnificent proportions, so conspicuous in the neighborhood 

 of section 24, towmship IH, range 15, as to be plainl}- visible from 

 Tucson, a distance of from twentv-live to thirtv miles awav. The 

 poppies {Kxc]t>ich<)lt2hi Dicricana) in this place develop a little later 

 than upon the mesa near Tucson or in the foothills of the Tucson 

 Mountains. This is explained by the difference in altitude and expos- 

 ure, and at times may be influenced by variation in rainfall as well, 

 althouu'h the rainfall of the winter is more evenly distributed than that 

 of th(^ summer season. Other plants which are abundant enough to 

 influence the vernal landscape by their floral colors are Linauthus 

 aurea^ Phacella arizonica^ P. crenulata^ Orthoearpus jf>?/?y>?/;'«-see??j,«i 

 jHthneri, J>alhi/a multiraduda ^ Lvp'iD^is hptopjn/lltin^ EnoplnjlJum 

 hniosuin^ and Bderhi ffracllis. None of these are altogether without 

 forage value, although the poppies and one or tw^o of the other species 

 mentioned are not eaten when there are other plants of greater palata- 

 iHlity. The other vernal vegetation consists of such small plants as 

 "patota" {Pectocarya linearis), Plagiohothri/s arizonicus, Eremocarya 

 inicrantha, Lotus liumistratus, L. humilis, Astragalus nuttallit, Indian 

 wheat {PI antago fastigiata and P. ignota), all of which are of forage 

 value. To these should also be added covena {Brodiiea capitata) and 

 the mustards {Lesquerella gordonii^ Sophia pinnata., S. incisa, and 

 Tludypodinin lasiopliyUum). 



The spring grasses on the open foothills amount to little in ,the 

 average season. The perennials mentioned above, especially the 

 gramas, make a .slight growth of root leaves in a favorable season, and 

 Aristida americana sometimes develops to the point of seed produc- 

 tion. Festuca octojiora is common throughout the area, but it is never 

 abundant enough to make any feed. Poa higelovii often furnishes 

 quite a little grazing around the bases of bushes and in other protected 

 areas in the arroj^os, where Chsetochloa grisehachii is of some value in 

 the fall. In autumn there is usually considerable feed produced b}^ 

 laml)'s-cpiarters {(Jhenopodimn fremontii). 



An enumeration of the main forage plants upon the rougher portion 



