ROBINIA. 121 



XXX. THE LOCUST TREE. 



Description. — This elegant and useful tree grows native 

 in mountain forests, from ilie Ohio River southward, and is 

 generally cultivated for timber, ornament or shade in nearly 

 all the States.* In May and June, amid the general festivi- 

 ties of nature, the Locust displays her pendant clusters of 

 white fragrant flowers, enlivening the dark green of the 

 graceful foliage. 



Analysis. — The Leaf Eegion^. — The leaves are com- 

 pound—of wliat form ? How do they differ from the leaves 

 of the Rose ? What are the number, margin, outline and 

 apex of the leaflets ? They are connected with the rachis by 

 a short stalk — petiolules. Are there any stipules ? A pair 

 of short, sharp spines occupy their place, especially in the 

 younger shoots ; we may call them stipidar spines. 



The Flower Region. — Compare the flower of the Locust 

 with that of the Pea, and notice the differences in the calyx, 

 banner, wings, keel, stamens, and especially the style (3). 

 Is the inflorescence centrifugal or centripetal ? It is a per- 

 fect example of a raceme. Are the stamens (1, 2) diadel- 

 phous? Compare specimens of the fruit (4) which have sur- 

 vived the Winter, or which ripen in September, with that of 

 the Pea. Is the pod 1-carpelled or 2-carpelled ? Has the 

 seed 1 or 2 cotyledons ? Any albumen ? 



Sensitiveness. — N"ote the tumid or fleshy bundles at the 

 joints between the petiole and stem, and the petiolules and 

 rachis. Have these any connection with the spontaneous 



* The Locust Tree attains its greatest perfection in Kentiicliy and Tennessee, 

 where it often rises to the height of 90 feet with a diameter of 4 feet. For strength 

 and durability its timber Is i)re-enunent, and tliercfore largely employed in shii)bnild- 

 ing, railway ties, and fence posts. As a shade tree its beauty is often marred by the 

 depredation of worms, which eat at the branches until they break and fnll. When 

 collected in groves it seems loss liable to this evil, and grows with great rapidity, often 

 reaching a height of 8 or 10 feet the first season. 



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