Indeed the roots are so great that at times they are very productive of firewood.
It is a mistaken localism to think that the mesquites are purely North American. Argentina has fifteen species of mesquite, while the United States has but six. (See pages 76-77.)
Dr. Walter S. Tower, geographer, late of the University of Chicago, reporting on his explorations in South America, says, "I have ridden all day through northern Patagonia with a temperature of 10° F. above zero, and have walked all the next day through continuous forests of algaroba. I think
little finger at its base and tapered out to a small filament at the end where I lost it." Mr. Forbes sent me the following item February 23, 1914: "W. M. Riggs says that in boring a well in the San Simon Valley, using a drop auger that brought up a core, they found fresh living roots at a depth of eighty feet. There were growing at that point greasewood, sagebrush, and scrubby mesquite. The roots must have been mesquite. There was an earthquake crack near by which may have facilitated the penetration of the roots. Earthquake, 1886, Well bored, 1909."
The American Naturalist, Vol. XVIII, May, 1884, "The Mesquite," by Dr. V. Havard, U. S. Army: "Sometimes in the Southwest tents are pitched on claims where no timber or fuel of any sort is visible. It is then that the frontiersman, armed with spade and ax, goes 'digging for wood.' He notices a low mound on whose summit lie a few dead mesquite twigs; within it, he finds large, creeping roots, which afford an ample supply of excellent fuel. These roots can be pulled out in pieces fifteen or twenty feet long with a yoke of oxen, as practiced by the natives in the sandy deserts of New Mexico and Arizona, where no other fuel can be had.
"Of the vertical roots, the taproot is often the only large and conspicuous one. It plunges down to a prodigious depth, varying with that at which moisture is obtainable. On the sides of the gulches one can track these roots down thirty or forty feet. They branch off and decrease in size if water is near by; otherwise they, even at that depth, retain about the same diameter, giving off but few important filaments. How much farther they sink can only be conjectured.
"Between these heaps of shifting sand are sometimes found large, vigorous mesquite shrubs, the only aborescent vegetation there. The inference would be that water, although too deep for the ordinary shrubs of the country, is accessible to the mesquite and should be reached at a depth of about sixty feet, a conclusion practically verified by the digging of wells along the Texas-Pacific Railroad.
"Mesquite posts, much used in fencing, are said to be indestructible whether under or above ground.
"As fuel, the wood from both root and stem is unsurpassed. It is the most commonly used from San Antonio, Texas, to San Diego, California."
