A NEW WALNUT 



Mutant Somewhat Similar to Live Oak Appears in California in Four Different 



Localities — Not a Walnut-Oak Hybrid Origin of All Walnut 



Species Possibly by Mutation. 



Erxest B. Babcock 

 Professor of Genetics, College of Agriculture, University of California, Berkeley, Calif. 



IX THE spring of 1901, in a southern 

 California nursery owned by D. C. 

 Disher, there appeared a dozen or 

 more seedlings, the first recorded 

 specimens of a new form of the native 

 California Black Walnut, Juglans cal- 

 fornica Wats. Two of these trees still 

 remain where they were first trans- 

 planted from the seed bed while several 

 were given away and are now growing 

 at various places in California. The 

 two that remain on the site of their 

 origin have been described and named' 

 as a new variety, quercina, because the 

 general appearance of these trees, with 

 their small, dark green leaves, is some- 

 what like that of the California Coast 

 Live Oak, Querctis agrifolia Nee. Fig. 

 16 shows these trees as they appeared in 

 1907. Their similarity to oaks is not in 

 specific details but in general apj^ear- 

 ance, in spite of the fact that this same 

 form has been named ,^ but without 

 a proper botanical description, "Juglans 

 quercifolid" by another writer. I main- 

 tain that the leaves are not oak-like in 

 form, which is the important mark of 

 resemblance. Neither are they closely 

 similar in size, which is quite variable, 

 nor in color and texture, which are dis- 

 tinct from live oak as well as from black 

 walnut. Fig. 17 illustrates most of these 

 points, while fig. 18 shows that the fruits 

 of quercina are simply reduced black 

 walnuts. 



This lack of resemblance between the 

 new form of walnut and the live oak is 

 an important point when we consider 

 the claim set forth that this form is a 



natural hyljrid between walnut and oak. 

 It happened that the wild black walnut 

 tree which was the parent of the original 

 specimens of the new form, stood beside 

 a large Coast Live Oak tree and this 

 fact led Mr. Disher to think that his 

 peculiar walnut seedlings were natural 

 hybrids between oak and walnut. Under 

 the circimistanccs it is not strange that a 

 layman shotdd be led into error, but it 

 is difficult to understand how any one of 

 scientific training can persist in so evi- 

 dent a fallacy. To be convinced that 

 somebody not only maintains this fal- 

 lacy but is actively engaged in misrepre- 

 senting the true nature of these trees, it 

 is only necessary to read the following 

 communication.' 



, Cal. 



August, 1914. 



"President State Normal School, 



, Cal. 



"Dear Sir: 



"I am now able to offer you what I believe 

 to be the rarest and the most remarkable tree 

 in the world. It is a hybrid between a live oak 

 and the California walnut. It bears oak-like 

 leaves and walnuts. It has been named 

 Jughins quercifoiia. It is the dominant of 

 Mendel from which I should be able to rear 

 a recessive tree bearing walnut-like leaves 

 and acorns. 



"I have sold many of these trees to Kew, 

 Edinljurgh, Berlin, New York and elsewhere. 

 I can supply these dominant trees at S 10.00 

 each and probably reccssives next year. A 

 discount on dozen lots. 



"Crowing a dominant and recessive side by 

 side you would liave the most remarkable 

 demonstration of Mendel's law to be found on 

 earth. An oak bearing walnuts and a walnut 

 bearing acorns! 



"I am expecting to locate this tree at the 



'Babcock, E. B. Studies in Juglans I. Study of a New Form of Jiighitis ca'ifortiica Wats. 

 Univ. of Cal. Pub. Agric. Sciences, vol. 2, No. 1, 1913. 



"Pierce, N. B. A New Walnut. Science n. s. vol. 37, No. 955, p. 613, 1913. 



'This letter was sent to the writer by a member of the faculty of a state normal school with a 

 request for an expression of opinion as to its veracity. 



40 



