CHAPTER DC 



The Walnuts and Hickories 



The walnut family, or Juglandaceae, which includes the walnut^ 

 butternut, hickory and pignut, although a relatively small family^ 

 is by no means as limited as it seems. According to the current 

 interpretation of the botanists it includes six groups of forms, or 

 genera, and these genera contain, altogether, about two score 

 different kinds, or species. They are widely scattered throughout 

 the warmer parts of the North Temperate Zone, and unlike the 

 majority of their associates they have spread long distances south 

 of the Equator in South America and in the East Indies. 



The walnut family is of considerable interest for a variety of 

 reasons, chief among which, aside from the great economic impor- 

 tance of some of them, is their long line of extinct ancestors reach- 

 ing back some millions of years to the Cretaceous period, and the 

 wide geographical range and abundance of these ancestors, which 

 explain the often curious distribution of the existing forms shown 

 on the accompanying maps. 



Not all of the genera have developed the same methods for the 

 dissemination of their seeds and some, instead of forming the huge 

 nuts of our familiar walnuts have kept the seed part of their fruits 

 small and light, thus enabling them to produce large numbers of 

 seeds with the same amount of material and expenditure of energy 

 required for a single walnut. Furthermore, instead of depending 

 altogether on chance or hungry squirrels for the dissemination of 

 their latent progeny, the bracts that are normally present through- 

 out the family have been enormously developed and serve as -^ings. 

 This state of affairs is best developed in those trees known as 

 Engelhardtias and will be referred to on a subsequent page. 



The fruits unmistakably indicate the genera — those of the hick- 

 ory have smooth shells and a husk which splits more or less readily — 

 the walnuts and butternuts have a pitted rough shell and an entire 



