68 



WOODPECKEES IN RELATION TO TREES. 



THE WALNUTS AND HICKORIES (JUGLANDACE^e). 



The trees of this family furnish the most costly woods produced 



in the United States. They are frequently attacked by sapsuckers 

 and the resulting injuries are severe and often 

 ruin the lumber, except for fuel or heavy con- 

 struction. Serious defects have been observed 

 in the wood of 12 of the 19 native species, and 

 probably all of them are subject to sapsucker 

 injury. In black (fig. 18) and in Texan wal- 

 nut, the defects consist of heavy black stains 

 running far along the grain and black checks, 

 either rilled with loose plugs or open and 

 knotty. They spoil the ornamental appear- 

 ance of these woods. 



In hickory (PL X, figs. 2 to 4, and PL XI, 

 fig. 1) the blemishes consist of open black 

 checks (varying in size up to 2 by 4 inches), 

 sometimes soft walled or partly filled with 

 spongy growth, frequently connected with 

 gnarly fissures up to 2 inches in length, which 

 usually extend toward the bark. These are 

 surrounded by brown or black stains called iron 

 streaks, which penetrate more or less wood 

 adjoining the wound and follow the grain some- 

 l imes for many feet. They are serious in all the 

 species examined. Mr. Carlos G. Bates of the 

 'The hickory is oftentimes 



damaged beyond the effect of the streak. As the 



wound made by the bird heals over, a small lump 



is formed over the spot, and stimulated to hyper- 



trophied growth (by the lack of pressure where the 



bark has been removed). This in time becomes a 



sort of tubercle standing out at right angles to the 



stem and protruding through the bark. Sooner or 



later it ceases to grow, and the normal growth of 



the tree buries it, leaving a flaw in the wood equal 



to a large, loose knot." 



The abundance and extensiveness of stains and 



gnarly growth in hickory unfit the wood for orna- 

 mental purposes, and the fact that the iron streaks 



make the wood harder to work and that check- 

 ing takes place readily along them, spoils the 



wood for many of its most important uses. 



"The wood is heavy, hard, very strong, tough, 



Fig. 17.— Effects of sapsucker 

 work on wood of Carolina 

 poplar (Populus deltoides). 

 Large checks and gnarled 

 grain. 



Forest Service says: 



, 



Fig. 18.— Effects of sap- 

 sucker work on wood 

 of black walnut {Jug- 

 lans nigra). Holes and 



dark stains. (From 

 Hopkins.) 



