AMERICAN FOREST TREES 537 



wood exists in the United States. Its hardness is equally remarkable, 

 and is said to be due to crystals formed in the wood cells, and known as 

 "rhaphides." Its durability is probably equal to that of Osage orange, 

 mesquite, and catalpa, but it is not easy to fix a standard of durability 

 by which to compare different woods. Locust is the best fence post 

 wood in this country, because it is usually much straighter than other 

 very durable woods. The posts are expected to last at least thirty years, 

 and have been known to stand twice that long. 



For more than 1 50 years locust was almost indispensable in ship- 

 building, furnishing the tree nails or large pins which held the timbers 

 together. It supplied material for other parts of ships also, but 

 in smaller quantities. The substitution of steel ships for wooden lessen- 

 ed demand for locust pins, and in many instances large iron nails are 

 used to fasten timbers together. In spite of this, the demand for 

 locust tree nails is nearly always ahead of supply. 



The wood's figure is fairly strong, due to the contrast between 

 the springwood and that grown later, but not to the medullary rays, 

 which are small and inconspicuous. The wood is not in much demand 

 for ornamental purposes. Small amounts are made into policemen's 

 clubs, rake teeth, hubs for buggy wheels, ladder rungs, and tool handles. 



The tree grows rapidly where conditions are favorable, and very 

 slowly when they are not. Usually trees of fence post size are twenty 

 years old at least, but trunks thirty five years old have been known to 

 produce a post for each two years of age, though that was exceptional. 

 Railroads, especially in Pennsylvania, planted locust largely a few years 

 ago for ties. It has been reported that in some instances expectations 

 of growth have not been fully realized. 



CLAMMY LOCUST (Robinia viscosa) was originally confined to the mountains 

 of North Carolina and South Carolina where its attractive flowers brought it to the 

 notice of nurserymen who have enlarged its natural range a hundred if not a thousand 

 fold. It is now grown in parks and gardens not only in the United States east of the 

 Mississippi river and as for north as Massachusetts, but in most foreign countries 

 that have temperate climates. It is usually a shrub, but on some of the North 

 Carolina mountains it attains a height of forty feet and a diameter of twelve inches. 

 The wood is seldom or never used for any commercial purpose. The leaves are from 

 seven to twelve inches long, and contain thirteen to twenty -one leaflets. The flowers 

 appear in June, possess little odor, and are admired solely for their beauty. They 

 are mingled red and rose color. The pods are from two to three and a half inches long, 

 and contain small, mottled seeds. The wood is hard and heavy, the heart brown 

 and the sap yellow. In its wild haunts it is usually a shrub five or six feet high. 



NEW MEXICAN LOCUST (Robinia neo-mexicand) is a small southwestern tree, 

 seldom exceeding a height of twenty-five feet or a diameter of eight inches. It ranges 

 from Colorado to Arizona, and takes its name from its presence in New Mexico. It 

 reaches its largest size near Trinidad, Colorado. It is found at elevations of 7,000 

 feet. Leaves are from six to twelve inches long, and the leaflets number from fifteen 



