LEGUMINOSAE 



Locust Black Locust 



Robinia pseudo-acacia, L. 



HABIT. A tree 50-75 feet high, with a trunk diameter of 

 2-3 feet; forming a narrow, oblong crown of irregular, more or 

 less contorted branches. 



LEAVES. Alternate, compound, 8-14 inches long. Leaflets 

 7-21, short-petiolate, 1-2 inches long, about one-half as broad; 

 ovate to oblong-oval; entire; very thin; dull dark green above, 

 paler beneath, glabrous both sides. Petioles slender, pubescent. 



FLOWERS. May-June, after the leaves; perfect; showy 

 and abundant; very fragrant; borne on slender pedicels in loose, 

 drooping racemes 4-5 inches long; about I inch long; calyx short, 

 bell-shaped, 5-lobed, hairy; corolla papilionaceous, w'hite, 5- 

 petaled ; stamens 10. 



FRUIT. Late autumn, but persistent on the tree through 

 the winter; a smooth, dark brown, flat pod 3-4 inches long, con- 

 taining 4-8 small, flattish, brown seeds. 



WINTER-BUDS. Terminal bud absent; lateral buds min- 

 ute, 3-4 superposed, partially sunken within the leaf-scar, rusty- 

 hairy. 



BARK. Twigs smooth, green, more or less rough-dotted 

 at first, 'becoming red-brown and armed with prickles; dark 

 red-brown and thick on old trunks, deeply furrowed into firm, 

 sinuous ridges. 



WOOD. Heavy, very strong and hard, close-grained, very 

 durable in contact with the soil, brown, with very thin, pale 

 yellow sapwood. 



NOTES. -Native to the Appalachian Mountains, but much 

 planted in Michigan for ornamental and economic uses. Very 

 rapid of growth in 'youth. Short-lived. Seriously attacked by 

 borers. Spreads by underground shoots. 



