Trees of New York Htate 273 



LEGUMINOSAE 



Kobinia Pseudo-Acacia L. 



Locust, Black Locust, False Acacia 



Habit — A medium-seized tree usually 30-60 feet in height with a trunk 

 diameter of ^^>-2 feet, under optimum conditions sometimes 60-80 feet 

 tall Avitli a trunk 2-4 feet in diameter. In the open the bole is short, 

 dividinjj a few feet above the ground into a number of stout, ascending 

 branches Avhich form a narrow, oblong, open crown. The trunk of forest 

 grown specimens is often free of branches for three-fourths of its length. 



Laeves^ — ^ Alternate, odd-pinnately compound, 8-14 inches long, consisting of 

 7-19 subopposite or alternate leaflets arranged along a slender, puberulous 

 rachis which is grooved above and swollen at the base. Leaflets ovate- 

 oblong to elliptical, l%-2 inches long, mucronate or retuse at the apex, 

 rounded at the base, entire, at maturity dull, dark blue-green and glabrous 

 above, paler and glabrous below except on the midrib, borne on stout 

 petioles %-^4 of an inch long, turning yellow and falling early in the 

 autumn. 



Flowers — Appearing in late May or early June when the leaves are nearly 

 grown, perfect, irregular, white, fragrant, about 1 inch long, borne on 

 slender, reddish pedicels in drooping, puberulous racemes 4-5 inches long. 

 Calyx canipanulate, gibbous on the upper side, reddish gi-een and pilose, 

 ])prsisteiit, .j-lobed, the loAver lobe longer than the others, corolla resem- 

 bling tliat of a sweet pea, consisting of a broad, obcordate, reflexed 

 standard (one petal), marked on the inner surface with a yellow spot, 

 two oblong falcate wings (one petal each), and acurved keel (two petals 

 united below). Stamens 10, diadelphous, the upper free, the remainder 

 united into a cylinder which is cleft on the upper side and encloses the 

 style. Pistil consisting of a linear-oblong, stipitate ovary, a geniculate, 

 subulate style bearded toward the top on the inner side, and a small 

 terminal stigma. 



Pruit — A flat, oblong-linear, somewhat falcate, glabrous, reddish brown 

 legume, 2-4 inches long, ^> of an inch mde, borne on stout, thick-stemmed 

 racemes, early dehiscent but persisting on the trees into the winter. 

 Seed reniform, compressed, orange-brown with darker mottling, about 

 3/16 of an inch long, borne on a curved funiculus, 4r-8 to a pod. 



Winter characters — Twigs slender or rather stout on vigorous growth, 

 brittle, more or less zigzag, terete or angular in cross section^ glabrous, 

 light reddish to greenish brown. Divergent or slightly recurved stipular- 

 thorns present on vigorous growth. Terminal bud absent. Lateral buds 

 small, 3-4 at a node, superposed, imbedded in the twig under the leaf-scar, 

 at length erumpent. Mature bark thick, reddish or yellowish bro-\\Ti, 

 deeply furrowed into rounded ridges covered with squarish persistent 

 scales. 



Habitat — Moist, fertile mountain slopes and along stream courses in rocky, 

 gravelly or alluvial soils. Widely naturalized in eastern United States, 

 occurring about dwellings, along highways and in waste places as a 

 "weed" tree, spreading by means of root-suckers and often forming 

 extensive thickets. 



Range — OrigLnally confined to the slopes of the Appalachian Mountains 

 finin Peniisylvniiia to Ger<rgia. Now widely naturalized in the United 

 States east of the Rocky Mountains. Zones A, B, and C. 



Uses — A valuable timber species, easily propagated by cuttings and of rapid 

 growth, but in certain sections subject unfortmiately to the attacks of 

 several serious pests including the Locust Borer. Wood very hard, heavy, 

 strong, very durable, brown or greenish yellow with narrow, pale yellow 

 sapwood. Used for fence posts, insulator y)ins. tree nails, railroad ties, 

 in shipbuilding and for other purposes where strength, freedom from 

 checking, and durability in contact with the soil are requisite. Widely 

 planted both at home and abroad for timber and ornament. 



