Frost Effect on Forest Trees 39 



was scarcely touched. The small leaflets were entirely frozen. 

 In some of the creek bottoms, 80 to 95 per cent of the leaves 

 were killed. Nearly all the terminal shoots died on coppice 

 growth and new growth came from lateral buds. Seedling trees 

 of the same size in the vicinity were not so badly affected. 



Osage Orange, (Toxylon pomiferum Raf.) had the leaves 

 affected at the tip and along the side. The leaf curled and 

 wrinkled toward the injury since the growing zone was reduced 

 along the dead tissue. The leaf margins toward the north 

 were more injured than the south margins and buds on the 

 north side were also more seriously affected than those on the 

 south. The north end of a plantation which was protected by 

 a shelter belt was not affected in the least although the leaves 

 were further developed than on exposed sites. 



Russian Mulberry (Moms alba tatarica Loudon.) was not 

 greatly injured. The injury was distributed in definite spots along 

 the margins of the leaves except at the sinuses. Some trees 

 in a very high, exposed position had 50 per cent of the fruit 

 killed. The terminal leaves were principally affected. 



Hackberry, (Celtis occidentalis Linn.) had 40 per cent of 

 its leaves frosted. The margin and tip suffered most and made 

 the leaf very irregular. Most of the injured leaves showed 

 definite spots where killing occurred. The dead tissue soon 

 dropped out leaving perforations resembling the work of some 

 leaf-eating insect. 



Russian Olive, (Eleagnus angustifolia Linn.) was affected 

 at the tip of the leaf. The leaf curled and turned back. Whole 

 clusters of leaves were affected. 



Honey Locust, (Gleditisia triacanthos Linn.) in plantations 

 six feet in height, had the tips of all leaflets killed and in some 

 cases, whole leaves were killed. The tips quicky became yellow 

 and turned back. Black Locust, (Robinia pseudacacia Linn.) 

 had the margin of the leaves injured. Only a very few trees of 

 this species showed injury. 



Hardy Catalpa (Catalpa speciosa Warder.) had its small 

 leaves entirely killed. Leaves which were half-grown or lar- 

 ger had slightly injured tips and margins. The live portion of 

 the large leaves, curled backward with an effect very characteris- 

 tic of the species. Shoots eight to twelve feet in height in a 

 forest plantation which had been coppiced were severely injured, 

 probably because coppice growth started earlier than seedling 

 trees of the same age or of the same sipe. Japan Catalpa 

 (Catalpa pagoda} had the buds frozen back and had many 

 shoots killed. It is never as hardy as the Catalpa speciosa. 



Black Walnut, (Juglans nigra Linn.) had 5 per cent of the 



