179 



HONEY LOCUST. 



Gleditsia triacanthos, Linnaeus. 



GENUS DESCRIPTION This genus comprises about 11 species of trees which are usually 

 armed on the branches and trunk with simple or branched thorns. They are distributed in the 

 temperate part of Asia and eastern North America. Fossil representatives of this genus have 

 been reported from Europe. Three species are native to eastern North America, one inhabiting 

 Texas, one the southern and south-central United States, and one described here. The generic 

 name is in commemoration of the German botanist, John Gottlieb Gleditsch. 



FORM A medium-sized tree usually from 40-50 ft. high with a diameter of 1-2 ft. but 

 may reach a height of 140 ft. with a diameter of 4-6 feet. Trunk usually short but when, 

 grown in very close stands may be rather clean and long. Crown broad, obovate, round-topped, 

 high on account of lateral drooping branches. 



BARK On young trunks smooth covered with many, very conspicuous, raised, oblong lenticels; 

 on old trunks grayish-brown to almost black, sometimes smooth but usually roughened by a few 

 fissures and thick, firm, broad ridges with projecting edges. Bark on trunks is often covered 

 with many thorns. See Figs. 59 and 94. 



TWIGS Eather stout, zigzag, smooth, glossy, with enlarged nodes; greenish-red to brown, 

 covered with few, small, scattered lenticels which become larger in time; pith thick and white. 

 Twigs frequently bear thorns which are often branched and contain reddish-brown pith. 



BUDS Alternate; terminal bud absent; small, usually 3-5 at a node, placed one above another; 

 upper ones scaly and visible, lowest one not scaly, nor visible except as a dot. Some buds are 

 slow in de^ eloping. 



LEAVES Alternate, singly or doubly compound, 7-8 inches long. Petioles flattened, grooved 

 above, enlarged at base. When singly compound with 18-28 leaflets; when doubly compound 

 with 8-14 pinnae and each with usually 18-20 leaflets. Leaflets lanceolate-oblong, 1J-2 inches 

 long, rounded at the base and apex, somewhat serrate on margins. 



LEAF-SCARS Alternate, 2-ranked or more than 2-ranked, U-shaped; varying in width; 

 broadest about the 3 bundle-scars and narrower between. 



FLOWERS Appear about May or June. Polygamus, small, greenish. Staminate flowers 

 arranged in short hairy racemes with short stalks. Pistillate flowers in few-flowered, rather 

 elongated and solitary racemes. 



FRUIT A more or less twisted, flat, and reddish-brown pod, 10-18 inches long, containing 

 many flat, oval, brownish seeds. The pods are thin, do not split open, often persist into winter, 

 and occasionally are produced in large numbers. 



WOOD Ring-porous; rays conspicuous on account of their brilliancy; hard, strong, heavy, 

 durable in contact with the soil; heartwood bright reddish-brown with thin pale sapwood. 

 Weighs about 42 Ibs. per cubic foot. Used mainly for fence posts and rails, hubs of wheels, and 

 general construction. In time its use will be extended and it may be grown for timber. 



DISTINGUISHING CHARACTERISTICS The Honey Locust, also known as the Sweet Locust, 

 Thorn Tree, Three-tkorned Acacia, and Honey Shucks, can be distinguished by its large branched 

 thorns located above th> leaf-scars. A thornless variety is, however, known. The once-com- 

 pound or sometimes twice-compound evenly-pinnate and alternate leaves together with the 

 leathery fruit pod from 10-18 inches long and the grayish-brown to black bark often covered 

 with conspicuous oblong lenticels are also characteristic. A longitudinal section of a twig 

 just above the origin of a leaf or a leaf -scar will usually show five separated and superposed buds, 

 the upper scaly and externally visible, the lowest not scaly and hidden beneath the bark. 



RANGE Ontario through Pennsylvania to Florida, westward to Kansas and Texas. 



DISTRIBUTION IN PENNSYLVANIA Found as a native or planted tree in all parts of the 

 State. Its original distribution in this State was limited almost entirely to the region west 

 of the Allegheny Mountains, except a few local outposts east of them. At present it is common 

 as a planted tree in tho entire eastern portion of the State and in many places has escaped 

 cultivation. 



HABITAT It develops best in rich soil along moist river bottoms but will grow in any fertile 

 soil which is not too wet. It demands plenty of light. 



IMPORTANCE OF "THE SPECIES This tree is of little commercial importance as a timber 

 tree in Pennsylvania because it is limited in its distribution. Most of the existing trees of this 

 State are open grown and not forest grown, therefore, too knotty to be of any commercial 

 value. If properly planted it will produce excellent wood. It grows rapidly, is free from 

 insect and fungal enemies, has an attractive form, and bears graceful foliage. The leaves 

 come out late in spring jind, hence, it is not of much value for shade. 



