446 AMERICAN FOREST TREES 



Northwest who had no other maple, formerly manufactured sugar from 

 this tree, collecting the sap in wood or bark troughs and boiling it with 

 hot stones. 



The compound leaf does not necessarily take it out of the maple 

 group. It requires no great exercise of imagination to understand how 

 a lobed leaf, by deepening the sinuses between the lobes, might become 

 a compound leaf in the process of evolution. There may be no visible 

 evidence that the box elder's leaf reached its present form by that 

 process, but there is another maple which is at the present time develop- 

 ing a compound leaf in that way, or seems to be doing so. It is the 

 dwarf maple (Acer glabrum) of the Northwest coast. Lobed leaves 

 and compound leaves may occur on the same tree. 



The seeds of box elder resemble those of other maples. They ripen 

 in the fall, and are blown off by wind, few at a time, during several 

 months. The trees are from fifty to seventy feet high, and from one 

 and a half to three feet in diameter. The trunk is apt to divide near the 

 ground in several large branches, and is not of good form for sawlogs, 

 being often crooked as well as short. The small branches, particularly 

 those less than a year old, are usually nearly as green as the leaves. 

 This fact may assist in identifying the tree when the leaves are off. The 

 bark bears more resemblance to ash and basswood than to maple. 



The wood is lightest of the maples. It weighs less tban twenty- 

 seven pounds to the cubic foot ; has less than half the strength and about 

 forty per cent of the stiffness of sugar maple ; and is much inferior to it in 

 most mechanical properties. It is equal, if not superior to most maples 

 in whiteness. The pores are small, numerous, and scattered through 

 all parts of the growth ring, as is characteristic of maple wood. The 

 tree grows rapidly. The summerwood is a thin, dark line, separating 

 one annual ring from another. The medullary rays are many and 

 obscure, but when wood is sawed or split along a radial line, they are 

 easily seen, and show the true maple luster. 



The uses of box elder are similar to those of soft maple. The wood 

 is seldom reported under its own name. In fact, an examination of wood- 

 using reports of various states, shows that in only two states, Michigan 

 and Texas, has box elder been listed separately. Its uses in the former 

 state were for boxes, crates, flooring, handles, woodenware, and interior 

 finish, while in Texas it was made into furniture. The tree is of com- 

 mercial size in at least thirty states, and is cut and marketed in all of 

 them. Tests of the wood for pulp are said to be satisfactory, and it finds 

 its way in rather large amounts to cooper shops where it is made into 

 slack barrels. It is cut as acid wood along with other maples, beech, and 

 birch, and is converted into charcoal and other products of distillation. 



