RELATION OF EARLY MATURITY TO HARDINESS. 



217 



This rating is given in the following table, where "1" indicates extreme 

 earliness and hardiness, and "6" extreme lateness and tenderness to 

 winter's cold. 



Table I. — Black walnut trees from seed froin various states, ranked 

 according to earliness and hardiness. 



States from which seed was obtained. 



South Dakota. . 



Nebraska 



Colorado 



loYv^a 



Pennsylvania . . . 



Ontario 



Missouri 



Illinois 



Ohio 



California 



Virginia 



Oklahoma 



Kentucky 



North Carolina. 

 South Carolina. 



Tennessee 



Georgia 



Alabama 



Rank of trees. 



There is here, certainly, a very close relation between early maturity 

 in fall and hardiness in winter. Apparently these trees have adapted 

 themselves to the length of the growing season in their native homes 

 (whether through natural selection or direct effect of climate — influence 

 of habit — does not appear) and do not easily change their habit of 

 growth when moved to a new climate. While in general the Northern 

 trees planted in Nebraska are earlier in ripening in fall and more re- 

 sistant to cold in the winter than Southern trees, there is also something 

 of the same difference between the Western and Eastern trees in favor 

 of the former. Perhaps this means that trees adapt themselves to short 

 seasons of growth whether the season is cut short by early fall frosts, 

 as in the North, or by dry weather in fall, as in many parts of the West. 



Honey Locust. — Observations made in spring to learn the amount 

 of winter injury sustained by the trees from different states, and observa- 

 tions in the fall to determine their relative time of ripening, show that 

 honey locust trees are no exception to the rule established for black 

 walnuts, namely, that trees accustomed to the longer growing season of 

 states to the south of us do not at once adapt themselves to our com- 

 paratively short season, but continue to grow late in fall and are con- 

 sequently injured more or less seriously by our cold winters. The 

 relative difference in time of ripening between honey locust trees from 



