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. Petieles 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, white, 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. 

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