74 



WOODPECKERS IN RELATION TO TREES. 



checking on a line with them. For cabinet or other work requiring 

 sightliness, or where strength is required in any but large pieces, 

 chestnut with abundant sapsucker work would be useless. (Speci- 

 mens from Pickens, W. Va.) 



Black oak (Quercus velutina). — The defects produced in this tree 

 by sapsucker pecking are large, widely 

 open, black-walled checks surrounded by 

 much gnarled and stained wood (fig. 23). 

 These checks vary in size up to 1 by £ by 

 5 inches and constitute defects so extreme 

 that the lumber is useless for any struc- 

 tural purpose. (Specimens from Abbe- 

 ville, La.) 



Cow oak (Quercus michauxi). — The de- 

 fects produced in this wood are large to 

 very large black gnarly checks. These are 

 sometimes contiguous, forming a stained 

 crack following an annual ring (fig. 24), 4 

 inches horizontally and 2 to 3 inches ver- 

 tically. Open fissures extending toward 

 the bark and surrounded by much gnarly 

 wood are characteristic. The wood under 

 the wounds is usually soft and rotten. 

 The specimens examined show that wind- 

 shakes tend to occur along the line of sap- 

 sucker defects. The blemishes are large 

 and numerous, hence serious. Many wind- 

 fallen trees examined by the writer at 

 Abbeville, La., were so filled with defects 

 that they would not afford a single board 

 of marketable dimensions. The wood is 

 useless except for fuel. 



Colorado white oak (Quercus lepto- 

 phyUaf. — Numerous open knotty checks 

 stained dark brown occur in a trunk of 

 this species attacked by sapsuckers. They 

 arc surrounded by gnarly wood, and some 

 are one-half inch by 1 inch in size, being 

 equivalent to open knots of those dimen- 

 sions. When several occur along the same 

 wood layer they constitute a line of potential fracture, thus rendering 

 the trurfk more liable to injury by wind-shake. (A. A. and A. M. 301.) 

 Species of Fagace.e blemished. — Beech, chinquapin, chestnut, 

 tanbark oak, turkey oak, black oak (fig. 23), Texan oak, Spanish oak, 



,— Effects of 



on wood of black oak (QuerciM 

 velutina). Large gnarly checks. 



