56 SHADE-TREES IN TOWNS AND CITIES 



grows crooked, with a short, thick trunk and long strag- 

 gling branches, and forms an irregular head. These charac- 

 teristics are against its employment for street-planting. 



Western Catalpa (Catalpa speciosa Ward.). This is a 

 Western species which is very hardy, of rapid growth, and 

 has proved a much better tree for street use than the 

 common or hardy catalpa. 



Ailantus {Ailanthus glandulosa Desf.). The ailantus, 

 also spelled ailanthus, is sometimes used for street-planting, 

 but outside of the fact that it will thrive in the poorest soil 

 and amid the most unfavorable conditions of city streets 

 there is very little to recommend it. When young, the 

 ailantus is vigorous and shapely, if properly trained, and 

 its large leaves are green until frost, but most old trees pre- 

 sent a very scraggly and unsightly appearance. The tree 

 possesses little grace in winter after the large compound 

 leaves fall and the thick, rigid twigs are revealed. At blos- 

 soming time the odor of the staminate or male flowers is 

 extremely unpleasant. Where other trees will grow the 

 ailantus should not be considered. 



THE LOCUSTS 



The Black Locust [Robinia pseudacacia Linn.) and the 

 Honey Locust {Gleditsia triacanthos Linn.) are sometimes 

 used as shade-trees. The former is successfully cultivated 

 in Paris, where the top is kept small and spherical, and the 

 branches thickly clustered. If allowed to grow freely, how- 

 ever, this tree does not form a round, compact head, but is 

 angular in form. Its branches are extremely brittle, its foli- 

 age short-lived, its pods persistent and given to sprouting. 



In the city of Washington there are a few streets planted 

 with the honey locust. They do not look so beautiful as 



