BULLETIN 231] WALNUT CULTURE IN CALIFORNIA. 161 



between Vacaville and "Winters, there is a large Paradox tree in the 

 dooryard near the corral which is probably of this cross. It is a par- 

 ticularly thrifty, beautiful tree, bearing fair crops of medium-sized 

 nuts of the usual Paradox type. In the vicinity of Goleta, in Santa 

 Barbara County, there is a considerable number of nigra trees planted 

 along the road on the county road from Santa Barbara to Goleta. 

 Intermixed with these nigra trees are numerous individuals of the 

 southern California black species, while on either side of the road are 

 extensive groves of English walnuts. In this instance a general mix- 

 ing takes place and among the seedlings of the various trees may be 

 found all sorts of freaks and hybrids. Nuts from the nigra trees give 

 a majority of straight nigra seedlings, some of the Royal type (having 

 crossed with the California black), and a considerable proportion of 

 strong, lusty individuals of the Paradox type, as shown by their leaves 

 which closely resemble those of the English walnut. Nigra trees come 

 out so much later in the spring than most of our English walnut trees 

 that it is remarkable that any cross takes place between these species. 

 Apparently, however, the English pollen either retains its vitality for 

 several weeks or there are some very late catkins which coincide in 

 development with the bloom of the nigra trees. These nigra Paradox 

 trees obtained from the Goleta nuts appear to be of an especially 

 thrifty, vigorous, hardy nature. 



The large old Juglans major, or Arizona black walnut tree, which 

 we have described as standing on the Harbison ranch near Vacaville, 

 crosses freely with English walnuts in the vicinity, and usually about 

 40 per cent of the seedlings from this tree are of the Paradox type. 

 It is reasonable to suppose that the tree also crosses with the northern 

 California black walnut, many large specimens of which stand close 

 to this Arizona tree, but the pure seedlings of the northern California 

 and major are so much alike that we have not been able to distinguish 

 any hybrids between these two in the nursery. 



Our experience, so far as it goes, seems to indicate that the English 

 walnut and the Paradox do not cross very readily, even though the trees 

 stand close together in the same orchard. Either this is the case or else 

 the resulting seedlings are indistinguishable from those of the Paradox 

 fertilized with its own pollen. Almost all Paradox trees are very light 

 producers and their seedlings are of a fairly uniform type, with no 

 individuals among them of exceptional vigor or differing noticeably in 

 appearance from the majority. Only in the case of the Strong tree 

 above mentioned have we found undoubted new crossing with the 

 English walnut among the seedlings, and this tree, as we have said, 

 resembles its black walnut parent much more than the English. Among 

 its seedlings there is always a large percentage of undoubted first 



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