24 CIRCULAR 17 8, U. S. DEPARTMENT OF AGRICULTURE 



by the presence in it of these spiny pods, the sheepmen prefer the 

 smoother varieties. McKee calls attention to the fact that, while 

 this species does best on heavy but fairly well-drained loams, it will 

 grow in almost any soil, even if somewhat alkaline, provided it is 

 not too arid, and will withstand wide variations of moisture, soil 

 texture, and shade (18). 



AUFAUFA 



Alfalfa {Medicago sativa) is regarded as second only to timothy 

 as a forage crop in North America. It is especially adapted to 

 warm, fairly dry regions with a deep soil, preferably of limestone 

 origin, although some hardy varieties such as Grimm will withstand 

 cold as low as —20° or —30° F., provided it is dry. Heavy tillage, 

 such as plowing and harrowing, is necessary to get alfalfa estab- 

 lished, and the species has been little used in artificial range reseed- 

 ing. Tests made have generally proved unsuccessful, but breeding 

 experiments with certain strains give promise of developing- races 

 of this choice legume that will prove suited to the adverse growing 

 conditions of portions at least of the western range. 



AJLFILERIA 



" Filaree " {Erodiuiii cicutanum) is an excellent forage in years 

 of good rainfall in many parts of the arid Southwest and in portions 

 of California. It was brought in from the Old World, presumably 

 from Spain and Mediterranean region, and has spread naturally 

 over much of the Southwest and as far north as central Idaho. 

 Alfileria begins growing during the winter rainy season, and at 

 that time, if moisture is sufficient, furnishes an abundance of highly 

 valuable green forage. When this moisture is dissipated the plant 

 dries up but often remains edible and palatable until utilized. Samp- 

 son {28) found that nearly 30 per cent of the early reseeding experi- 

 ments with this species gave good results. The seed must either be 

 exposed to the weather for several months or the seed coats broken 

 in order to induce satisfactory germination. Thornber {33) calls 

 attention to the fact that establishment of alfileria stands from seed 

 sowing is likely to prove a rather slow process. Probably this 

 species is of most value for reseeding areas similar to those where 

 it has gained a foothold naturally or where it is likely to spread. 

 Sampson recommends fall sowing with 8 pounds of seed per acre 

 at elevations not exceeding 5,000 feet in California or 3,000 feet in 

 the North. 



AUSTEALIAN SALTBUSH 



Australian saltbush {Atriplex se^inibaccata) was introduced 

 throughout the semiarid section of the United States about 30 years 

 ago. The high hopes once held for this plant for improvement 

 of the range in dry, alkaline regions of the West have fallen some- 

 what short of realization, for the species has proved a failure except 

 in specific areas along the Pacific coast, in the San Joaquin and 

 Imperial Valleys of California, and in the Salt River, Yuma, and 

 Santa Cruz Valleys of Arizona {17^ 20). In these regions it has 

 become well established as a good range plant, producing herbage 

 during a season when other forage plants have dried up. 



