146 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION. 



Considering the characteristic and constant difference in the form of 

 the trees, both in old specimens and in the nursery, the most pronounced 

 difference in the vegetative period when the trees are grown side by side, 

 and the same difference under the same circumstances in relation to the 

 diseases mentioned, we feel, on the whole, extremely doubtful as to the 

 identity of the northern California type with that of the south. It 

 seems to us certain that the northern type is at least a distinct variety of 

 the southern, in which case Jepson's classification of it as Juglans cali- 

 f arnica var. hindsii would be acceptable. Still it is remarkable that a 

 variety so uniformly distinct from the original type in the larger size of 

 the nuts, the upright form of the tree, later foliation and earlier defolia- 

 tion period, slower sprouting of the nuts and different behavior under 

 certain climatic conditions should comprise all the northern California 

 trees without exception. It is also remarkable that so distinct a variety 

 should have developed in the north without the development of any other 

 distinct varieties in the south or other portions of the State. Almost 

 the only way to account for the northern California type as a variety of 

 the southern is to assume that the northern trees are all descended 

 originally from one individual tree, which tree happened to be of its 

 distinct type. 



We are considerably inclined toward another solution of the question, 

 namely, that the northern California trees represent the relics of an 

 almost extinct species, paralleling the case of several other trees found 

 in California. In this case the northern California walnut would prob- 

 ably be called Juglans hindsii Jepson. Even under this supposition, it 

 is true in all probability that the original trees of the northern type 

 found in the three localities mentioned were planted by the Indians 

 rather than representing an original, indigenous growth. What, then, 

 the history of the tree was previous to these plantings and when the 

 original planting in these localities took place must still remain a mys- 

 tery^ ... Present indications are that the Napa County ^station is the oldest 

 of the three, and it is possible that the tree was originally a 'native of 

 that portion of the State whence the nuts were carried by Indians to 

 other localities. 



OTHER NATIVE WALNUTS OF THE SOUTHWEST. 



In addition to the California species of black walnut, there have been 

 more or less distinctly recognized by botanists at least two other species, 

 namely Juglans rupestris and Juglans major, the range of these forms 

 extending over Arizona, New .Mexico, and Texas. Much uncertainty 

 has prevailed and still exists as to the identity and, limits of these 

 species, especially as to the limitations of Juglans rupestris. By some 



