498 swingle: Chinese tree of heaven 



having fertile stamens, do not produce nearly so much pollen 

 as the male trees. 



Other drawbacks to this species as an ornamental tree are its 

 habit of sprouting profusely from the roots and the fact that its 

 leaves and twigs are malodorous if rubbed or bruised even 

 slightly. Ailanthus trees, if cut off after they are once well 

 established, send up astonishingly vigorous shoots that some- 

 times grow 12 to 15 feet high in a single season and bear leaves 4 

 or 5 feet long. Because of this they are sometimes used as a 

 screen, being cut to the ground every year. 



AILANTHUS A FOOD FOR WILD SILK WORMS 



In China a silk worm, Attacus cynthia or Philosamia cynthia, 

 eeds on the leaves of Ailanthus and produces a very durable kind 

 of silk, similar to shantung or pongee. An account of the wild silk 

 worms of China was published in 1777 by the French Jesuit 

 missionary Martial Cibot. 17 He noted this tree under its Chinese 

 name, Ch'ou ch'un (tcheou-tchun), as one of the three species on 

 which the Chinese wild silk worm feeds. This Ailanthus silk 

 worm has been introduced into Europe and America and has 

 become naturalized in the eastern United States. It would be 

 hard to find a plant capable of producing a larger bulk of leaves 

 than the Tree of Heaven, and as these so-called wild silk worms 

 feed out of doors and can endure cold and even wet weather, it 

 would seem worth while to experiment in raising them in this 

 country for silk production. 



17 Cibot, Pierre Martial. Sur les vers a soie sauvages. Mem. concernant 

 l'hist. les sciences etc. des Chinois, 2: 575-598. Paris, 1777 



