A. PATULA. 



255 



number of varieties and minor forms. The difficulties encountered and the unsatis- 

 factory nature of the results are evidenced by the overlapping of the key characters, the 

 occasional lack of concordance between these and the descriptions, the admitted diffi- 

 culty of placing many of the forms, at least as to variety, and the frequency of supposed 

 hybrids. 



In order to avoid such confusion as exists in the European literature, it seems wise 

 to retain all of the "patula group" in one collective species and to admit under this a 

 limited number of closely defined subspecies. The precedents of Gray and Watson are 

 followed in adopting patula for the specific name, notwithstanding the fact that has- 

 tata appears before it on the page where both were originally published. The distinc- 

 tions between these two lie wholly in the shape of the leaves and of the bracts. Since 

 these differences vanish when intermediate forms occur, and .since the shape of the 

 bract is looked upon only as another expression of the leaf-character, the criteria can 

 have not more than subspecific value. On the other hand, these two subspecies are 

 much more than ecologic forms. Over much of the area of distribution they remain 

 entirely distinct and easily recognizable, even when growing side by side. 



Table 24. — Variation in Atriplex patula hastala and A. patvla typica. 



' Lower leaves wanting; probably referable to typica on the character of the shape of the bracts. 



Various attempts have been made to differentiate these and other forms on the basis of 

 size and sculpturing of the bracts. A hint as to the unreliability of these criteria is given 

 in the subjoined table. The tabulation of a much more extended series has been made, 

 but since it merely confirms the results of the first examination it is not given. 



The subspecies glabriuscula is placed between the two just discussed because of its 

 evident derivation from hastata, from which it scarcely differs, except in the larger upper 

 leaves which persist throughout the inflorescence. It is much more abundant in Europe 

 than on this continent and seems to be especially suited to boreal conditions. The close 

 similarity in most characters to those of A. maritima, especially the tendency toward a 

 hardening of the bracts, suggests that glabriuscula may represent the primitive stock of 

 the group of species sometimes known as section Obionopsis. The subspecies litorali-s 

 may be looked upon as a development from patula in a direction opposite to that of has- 

 tata, since its leaves have undergone the greatest amount of reduction in width. In 



