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AMERICAN FORESTRY 



HOW CHILDREN STUDY TREES 

 Black locust exhibit, illustrating the life history and commercial 

 uses of this tree. The exhibit won a prize in a tree contest in a 

 Washington, D. C, Normal School. 



flowers and is valuable for conserving rainfall on 

 the dry slopes on which it grows. 



Honey locust is a title sometimes given to the 

 black locust in New England because of its frag- 

 rant, honey-laden bloom. The true honey locust 

 (Gleditsia tricanihos) differs in so many respects 

 from the Robinias or true locusts that botanists 

 give it a separate classification, but the leaves, 

 fruit and wood show that they are closely related. 

 The honey locust may have a single leaf-stem, 7 

 to 9 inches long, furnished with 9 to 14 pairs of 

 leaflets, or the leaf-stem may divide into 8 to 14 

 branches and each branch bear 9 or 10 pairs of 

 smaller leaflets. Honey locust leaflets are in pairs 

 the entire length of the stem, while black locust 

 has a single leaflet at the tip of the stem bearing 

 the paired leaflets. Black locust has oval leaflets 

 with even margins; honey locusts are oblong and 

 the margins are slightly wavy or notched. Black 

 locust has short, stout spines that are merely at- 

 tached to the bark, like prickles of rose bushes, 



and drop off or are easily broken off. Honey locust has 

 long branching thorns that are part of the wood of the tree 

 and cannot be easily detached except by cutting. The fruit 

 of the black locust is a straight, dull brown pod, 2 to 4 

 inches long; the pod of honey locusts is 6 to 18 inches long, 

 bright brown or purplish in color and always more or less 

 curved and twisted. The pods of black locust split open 

 easily; those of honey locust must be torn apart. The 

 differences between these trees enable one to readily dis- 

 tinguish them at all times of the year. 



Honey locust is native from Ontario to Florida, west 

 to Kansas and Texas. Ordinary trees are 50 to 75 feet high 

 and 1 8 inches to 2 feet in diameter, but in the rich bottom 

 lands of the Ohio valley honey locusts have been known 

 to grow to a height of 140 feet and a diameter of 6 feet. 

 In the forest, it usually does not have a trunk quite as 

 straight and clean as black locust. In the open it branches 

 low and forms a spreading, rounded top. The lower 

 branches extend at nearly right angles to the trunk, and 

 the twigs droop with considerable grace. The bark of 

 the trunk is very dark colored and may be rather smooth, 

 but on large trees is commonly cleft into very broad, 

 thick ridges. The twigs have a zigzag growth, and are 

 covered with shining brown or greenish-red bark. The 

 older twigs frequently have strong, shining brown thorns, 

 and the trunk is usually equipped with still larger weapons 

 of defense. These thorns are specially developed branches. 

 The fact that most of the thorns are branched near the 

 base to form a cross, has caused the tree to be called the 

 three- thorned acacia and the Acacia of the Passion. 



Four of five buds are found at each leaf scar, but only 

 the upper one of these buds can be seen, and that is exceed- 

 ingly small. The flowers appear late in the spring, in small 

 greenish clusters. They are fragrant and honey laden 

 but not showy, nor are they pea-shaped, like those of the 



LOCUST AS A SHADE TREE 

 HoneyJIocust planted as a street tree in Kansas. The honey locust is free from the serious 

 insect and fungous enemies that beset the black locust, and is in every way an admirable 

 tree for shade and ornamental planting. It is one of the hardiest trees for planting in the 

 naturally treeless area of the United States. 



