In subgroup Ila, spot 9 is smaller than in any of the previously described sub- 

 groups except Id where it is of similar size. However, the brilliancy of this spot in 

 Ila is decidedly less intense than that found in any of the collections placed in 

 group I; nevertheless, spot 9 in Ila remains somewhat iridescent. Spots 12, 14, and 

 25 occur in this subgroup (fig. 5). In both Ila and lib, spots 5 and 6 are small and 

 dull yellowish-brown. They are similar in size and color to those found in la. 



In subgroup lib, spot 9 is very small, often not exceeding one-half inch in diam- 

 eter, and it exhibits little or no iridescence. In most chromatograms of subgroup lib, 

 spots 12 and 25 are missing; and when present they are small and only faintly colored. 

 Spot 14 is always present in lib, although occasionally the color of this spot is dark 

 violet rather than the usual blue-gray found in all other groups (fig. 6). On the basis 

 of morphological examinations, it seems apparent that collections representing sources 

 in subgroups Ila and lib would be in the subgenus A. tridentata tridentata. Further 

 observations may show Ila to be considerably integrated with la. 



GRAZING 



The groupings already described are related to the degree of grazing by deer and 

 livestock. However, observations indicate that plants in group I are much more pala- 

 table than those in group II (fig. 7). This was true on the row plantings on State 

 Fish and Game lands northwest of Price, Utah, in January 1969 and 1970, and also where 

 natural representatives of these two major groups were found, on the local winter range. 



Figure 7. — Comparison of subgroup Ic from Hobble Creek (left) with subgroup lib 

 from Indianola 3 in January 197 3 when grazing averaged 60 and 5 percent 

 respectively . Plants of these sources had attained a similar height of 

 about 24 inches when deer began to graze them in mid-November. 



6 



