16 HOUGH'S AMERICAN WOODS. 



and the lower two sometimes united; stamens 3-5, occasionally more (and part of them 

 may be abortive), distinct, opposite the sepals and inserted on the base of the calyx; 

 style short. Fruit a flat pod containing solitary or numerous flat seeds and often a 

 sweet pulp. 



Trees furnished with branched thorns which are usually supra-axillary. (Named 

 in compliment to John d> OHeditsch, a botanist), 



28. GLEDITSCHIA TRIACANTHOS, L. 



HONEY LOCUST, BLACK OR SWEET LOCUST, THREE-THORKED ACACIA. 



Ger., Dreidorniger Homgdorn; Fr., Fevier a trois epines ; Sp., Algarrobo 



de miel. 



SPECIFIC CHARACTERS. Leaves irregularly bicompound, single leaflets being often 

 replaced by pinnae; leaflets lanceolate- oblong, obtuse, and slightly serrate; thorns 

 very stout, from 2-12 inches (5-30 cm,) in length and usually triple, i. e., each 

 sending out two thorns as branches. Flowers (June) as described for the genus. 

 Fruit a flat linear brownish-red pod about 1 in. (2.5 cm.) or somewhat more in 

 width and often 1 ft. or more in length, twisted and contorted and containing a pulp 

 which is sweet at first (but after a few weeks ferments and becomes very sour) and 

 many hard, flat, brown seeds. 



(The specific name, triacanthos is from the Gk. rpfTS, three and a navQa, thorn, 

 in allusion to the triple or three branched thorns.) 



A tree sometimes 100 ft (30 m.) in height, or rarely taller, and 3 or 4 

 ft. (1 m.) in diameter, usually noticeable on account of the ugly branched 

 thorns, sometimes a foot in length which bristle out along its trunk and 

 branches in a most formidable manner (as the writer was -very forcibly 

 impressed, once in younger days, k when he had occasion to ascend one of 

 these trees after his pet owl which had escaped to its top). The foliage 

 is so thin and light that it offers little obstruction to the sun's rays. 

 After the leaves have fallen the long, contorted pods swing and rattle in 

 the wind for a long time, many until spring. The bark is blackish, 

 hard and smooth until with age it checks and becomes detached in 

 plates. 



HABITAT. A tree naturally of the central region of the United 

 States from Michigan nearly to the Gulf and particularly along the 

 Mississippi and Ohio river basins, growing best in the rich bottom lands. 

 It is extensively introduced, however, and apparently becoming natural- 

 ized in the Atlantic States. 



PHYSICAL PROPERTIES. Wood heavy, hard, strong and durable in 

 contact with the soil. It is of a rich reddish-brown color with a yellow- 

 ish-white sap wood. Specific Gravity, 0.6740; Percentage of Ash, 0.80; 

 Relative Approximate Fuel Value, 0.6686; Coefficient of Elasticity, 

 108579; Modulus of Rupture, 923; Resistance to Longitudinal Pressure, 

 500; Resistance to Indentation, 168; Weight of a Cubic Foot in Pounds, 

 42.00. 



