The Mesquites and Screw-Beans of the United States

Benson, L.

The mesquites and screw-beans are among the dominant and most significant plants in the Southwest, and they rank high among the trees and shrubs which give unique character to the desert. Especially the mesquites are of value as range food plants, because the highly nutritous seeds and the young shoots are eaten by cattle and many other animals. They are also a pest on the ranges, since frequently thickets of the young plants exclude cattle from grasses and other forage plants. Mesquites are important as bee plants, and at one time they were of great value as timber trees in desert areas where no lumber was available. They are still much used for fence-posts and for fire-wood, and since the wood is hard and reddish and capable of taking a high polish, it is used for trinkets and novelties. A gum, which exudes from the stems, is collected and sold for manufacture of gumdrops and mucilage. The seeds were used by the Indians and by the white pioneers for making flour, and as a source of bread they were one of the staple desert foods. Classification of the mesquites and screw-beans has been in almost constant revision and dispute for a century. Some authors have considered them to be congeneric, and others have not. Despite the considerable differences noted in the key to the sections below, it is the opinion of the writer that the similarities of the sections Algarobia and Strombocarpa outweigh the differences. It is to be noted that while some of the characters used in the key are of value in segregating the few species of the section occurring in the U.S., they are not necessarily characters constant for the entire sections.

The Mesquites and Screw-Beans of the United States

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