A VARIATION IX THE BLACK WALNUT. 

 L. H. pam:\iel and charlotte m. kixg. 



Several years ago Professor A. B. Noble of the- English De- 

 partmient of Iowa State College called my attention to a pe:'iiliar- 

 walnut 'which he thought might be hybrid l^etween the buitternnt 

 {Juglmis cinerea) and the black walnut {Jnfilaiis nigra). He 

 again called my attention to the same tree last fall, in October, 

 1917. 



The history of the tree, as given to me by Professor Noble, is 

 as follows : The tree came up from some walnuts gathered and 

 discarded. It has borne a crop of walnuts for a number of 

 years. All fruits on this tree have l)een essentially the same. 

 Other seedlings from the same batch had normal walnuts. The 

 trunk of the variating walnut tree appears to he of the black 

 walnut type, a straight trunk with upright branches. The bark 

 of the young stems and branches is light brnwn. covered ^nth 

 thin scales; the bark of the main trunk is cf the same general 

 color, with scales more deeply divided, more roughened and 

 darker in color than the butternut. The leaves look like those of 

 the common black walnut, the leaflets are ovate lanceolate and 

 taper pointed, smooth above, lower surface and petioles downy. 

 The fruit is somewhat pyriform, contracted near the l>ase. light 

 yellowish green, somewhat roughened by small hairs and is about 

 the same size as the common black walnut. The nut resembles the 

 nut of the common black walnut in that it is dark brown, cor- 

 rugated, not ribbed as the butternut. The odor of the tree as 

 well as the taste of the nut was that of the walnut. 



In cut;ting off some of the branches some five inches of the 

 stub were allowed to remain on the tree and a part cf the bark 

 was removed from the body of the tree, leaving this exposed 

 to the weather. When the stulv was proprely cut close to 

 the trunk of the tree it was found that this portion of the wood 

 was dark in color, showing the regTilar character of the heart 

 wood. The remaining wood was light in color, the color of the 

 sap wootl of the walnut. This led those who trimmed the tree 

 to believe that it must be a hybrid between the l>lack walnut 

 and buttennit. We have not scanned the literature on hybrids. 

 The Juglans nigra has been hybridized with several species of 

 Juglans. notably the California walnut, Juglans calif ornica. 



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