Tobosa is an erect perennial very similar in general appearance 

 to galleta (H. jamesii). It ranges from western Texas to Ari- 

 zona and south into Mexico. It grows most abundantly in the 

 southern part of New Mexico and Arizona on the finer, somewhat 

 compact soils on open flats, swales, and depressions and, to some 

 extent, on similar soils in the foothills. It occurs more sparsely on 

 sandy or gravelly soils, mainly at elevations between 3,000 and 5,000 

 feet. This grass is very common on areas subject to flooding in the 

 rainy season, where it attains its best development; it is considered 

 the climax vegetation in certain adobe clay depressions and swales. 1 

 Under such conditions, it may form a pure stand of coarse sod grass 

 over areas as large as 1 or 2 acres. On the dry sites tobosa grass 

 occurs in scattered stands in large tufts and is fairly resistant to 

 drought although it suffers more during extended periods of dry 

 weather and is slower in recovering from such a setback than are 

 many of its associates. Although preferring areas subject to flood- 

 ing, tobosa is one of the first grasses to die when submerged for 

 periods of several months. It is also intolerant of shifting sands. 1 



Burrograss (Scleropogon bremfolius) and either alkali sacaton 

 (Sporobolus airoides] or sacaton (S. wrightii) are common associ- 

 ates of tobosa on adobe clay soils. On sandy clay or gravelly clay 

 loams, tobosa is often the most important forage species growing 

 in association with blackbrush (Flourensia. cernua), black grama 

 (Boutelwua eriopoda), side-oats grama (B. curtipendula) , dropseeds 

 \Sporobolus spp.), and muhly grasses (Muhlenbergia spp.). 



Tobosa is good in palatability when it is green and succulent, 

 especially for cattle and horses. The species withstands grazing 

 very well during the summer rainy season when its main growth 

 occurs. Tobosa range should be grazed at that time as its grazing 

 capacity is then maximum. Campbell 1 states that "it may be 

 grazed up to 60 percent of its herbage production each summer 

 without injury or without materially hindering the succession on 

 adjacent areas supporting lower stages." Tobosa may be utilized 

 to some extent in the fall but is of little value as winter forage be- 

 cause the stems and leaves soon become so dry and tough after 

 growth ceases that livestock pass it by if other feed is available. 

 Tobosa range, adjoining black grama range, affords a good combina- 

 tion, as the former may be grazed during the growing season, which 

 facilitates deferred grazing on the black grama range. Such man- 

 agement enables these plants to produce the maximum volume of 

 forage before being grazed. 



Tobosa produces a fair amount of seed of moderate viability, and 

 is not an aggressive seeder on the range. The strong rootstocks, 

 although slow in spreading, provide the surest means of reproduc- 

 tion and make the plant resistant to trampling and a very valuable 

 soil binder. 



1 Campbell, R-. S. PLANT SUCCESSION AND GRAZING CAPACITY ON CLAY SOILS IN SOUTHERN 

 NEW MEXICO. Jour. Agr. Research [U. S.] 43 : 1027-1051. 1931. 



