332 AMERICAN FOREST TREES 



only advantage over gum was that it was harder and wore longer. So 

 involved and interlaced are the fibers of black gum, that they cross one 

 another not only at right angles, but at every conceivable angle. This 

 can be seen in examining very thin pieces with a magnifying glass. 



The wood is not hard, but is moderately strong, and stiff. It has 

 been compared with hickory, but it is so inferior hi almost every essen- 

 tial that no comparison is justified. 



Black gum weighs 39.61 pounds per cubic foot. It is very porous, 

 but the pores are too small to be seen by the naked eye, and are diffused 

 through the wood and form no distinct lines or groups. The summer- 

 wood is a thin dark line, not prominent enough to clearly delimit the 

 yearly rings of growth. The medullary rays are numerous, but very thin. 

 In quarter-sawed wood they produce a luster, but the individual rays 

 are practically invisible. The wood is not durable in contact with the 

 soil. 



The standing tree is apt to fall a victim to the agencies of decay. 

 Hollow trunks, mere shells, are not uncommon. The entire heartwood 

 is liable to fall away. The pioneers cut these hollow trees, and sawing 

 them in lengths of about two feet, made beehives of them. They called 

 them gums because they were cut from gum trees. Larger sizes, used 

 in place of barrels, were also called gums, but these were usually made 

 from sycamores. The black gum is not usually large. Individuals 

 have been measured that were five feet in diameter and more than a 

 hundred in height, but an average of sixty feet high and two in diameter 

 is probably too much, except in the southern Appalachian mountains 

 where the species attains its largest size. 



It is a tree which will always be easily recognized after it has been 

 seen and identified once. Its general outline, particularly when leaves 

 are off, is different from other trees associated with it. It might possibly 

 be mistaken for persimmon unless looked at closely; but there are 

 easily-recognized points of difference. Its branches are very small, 

 slender, and short. Its bark is rougher than that of any other gum, and is 

 much darker in color. It is the bark's color that gives the tree its name. 

 The leaves have smooth edges. In the fall they change to gorgeous 

 red, and one of their peculiarities is that half a leaf may be red while 

 the other half remains green. Toward the end of the season, the green 

 disappears. The dark blue drupes ripen in October. They do not seem 

 to be food for any living creature. 



Sawmills include black gum with tupelo in reporting lumber cut, 

 and generally call both of them gum without distinction. The woods are 

 quite different, and neither the standing tree nor the lumber of one need 

 be mistaken for the other. The range of black gum is much more 



