PLATE 15. LOCUST (Robinia, Gleditsia).
| Black Locust Tree and Bark (Robiniapseudacacia.) | |
| Honey Locust(Gleditsia triacanthos). | |
| LocustWood. | |
LOCUST, MESQUITE. (Robinia, Gleditsia, Prosopis.)
The name Locust applies to species of three distinct genera, all of which belong to the family Leguminosæ. The black locust (Robinia pseudacacia), the honey locust (Gleditsia triacanthos), and the Mesquite or honey locust (Prosopis juliflora) are principal representatives of their respective kinds. The first-named genus is North American, the other two have species on both continents.
BLACK LOCUST (Robinia pseudacacia).
Black locust wood is tough, durable, unequalled for torsional strength and resilience, and is in every way in the first rank of American woods. It is fitted not only for exposed constructions, but for finer articles; hubs, pins, bolts, and trenails having no superiors. Trees develop rapidly when young, heart wood forming as early as the third year. Later growth and ultimate commercial value in the United States are much affected by insect borers, which practically limit the usefulness of the species. The black locust may be known by its clusters of large pea-blossom-shaped flowers, its bean-shaped pods, three to six inches in length, and by the prickles on the bark. The genus has six species, four of which are natives of the United States.[45] Robinia is from Robin, the name of an early French botanist. [p076] The black locust has been extensively introduced into Europe, both for ornamentation and for wood.[46]
The wood of the honey locust resembles that of the black locust, but is seldom used or appreciated save for fencing and similarly unimportant purposes. Trees grow rapidly and are not subject to the attacks of insects, so that they frequently attain to normal proportions. The flowers are much smaller than those of the black locust, but the pods are several times as long (twelve to eighteen inches). These often curl in drying and are thus rolled to some distance by the wind. Thorns or spines are present on some individuals and are often from three to six inches in length. The foliage resembles but is more delicate than that of the black locust. There is at least one other American species. Gleditsia is from Gleditsch, the name of a botanist.
Mesquite, also called honey locust, affords wood that is hard, heavy, and almost indestructible in exposed positions. The tree grows in the desert where vegetation would often seem to be impossible. The roots are developed to great size by their search for water, and are gathered and burned in the absence of other fuel. The trunks are small, but afford posts and ties. There are pods filled with rich edible pulp. Sixteen or more species belong to this genus, prosopis, of which one other, the screw-pod mesquite (Prosopis odorata), is found in the United States. [p077]