The tree’s geographical range does not fall much short of 3,000,000 square miles, and is equalled by few species of this country. It extends from New England across Canada to Alberta, thence to Arizona, and includes practically all the United States east and south of those lines. It thrives in hot and cold climates, and high and low elevations; in regions of much rain, and in those with little. That fact has been turned to account by tree planters, particularly in the years when the western plains were being settled by homesteaders. The box elder was the chief tree on many a timber claim where the letter of the law rather than the spirit was carried out. It afforded the earliest protection against scorching summer sun and the keen winds of winter about many a frontiersman’s cabin on the plains. It was the earliest street tree in many western towns. The people planted it because they knew it would grow, and they were not so sure of a good many other trees. Green ash was often its companion in pioneer plantings on the plains. Many towns which set box elders along the streets when they did not know of anything better, still have the trees, though they would willingly exchange them for something else. They are not ideal street and park trees; do not produce shapely trunks and crowns; and drop leaves all summer and seeds all winter. The tree is reputed to be short lived, yet some of those planted a generation or two ago show no symptoms of decline. There is no good reason why this tree should be called an elder, or an ash, except that its leaves are compound. If that is a reason, it might be called a hickory or a walnut, since they bear compound leaves. It is clearly a maple. Its fruit shows it to be so, and Indians of the far 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 developing 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.