SIMARUBACEAE 



Ailantluis. Tree of Heaven 



Ailanthus glandulosa, Desf. 



HABIT. A h,andsome, rapid-growing, short-lived tree, at- 

 taining a 'height of 50-70 feet and a trunk diameter of 2-4 feet, 

 with a spreading, rather loose and open crown and a coarse, blunt 

 spray. 



LEAVES. Alternate, pinnately compound, 1-3 feet long. 

 Leaflets 11-41 in number, 2-6 inches long and about one-third as 

 broad; ovate-lanceolate; entire with the exception of two or 

 more coarse, glandular teeth at the base; glabrous, dark green 

 above, paler beneath, turning a clear yellow in autumn or falling 

 without change; ill-scented. Petioles smooth, terete, swollen at 

 the base. 



FLOWERS. June, when the leaves are full grown; poly- 

 gamo-dioecious; small, yellow-green, borne in upright panicles 

 6-12 inches or more in length ; calyx 5-lobe'd ; petals 5, greenish, 

 hairy; stamens 10. Staminate flowers ill-scented, pistillate almost 

 free from odor. 



FRUIT. October; i-celled, i-seeded samaras, spirally 

 twisted, reddish or yellow-green, borne in crowded clusters. 



WINTER-BUDS. Terminal bud absent; lateral buds about 

 l /% inch long, subglobose, brownish, downy. 



BARK. Twigs yellowish to red-brown, velvety-downy; 

 thin, grayish and shallowly fissured on old trunks. 



WOOD. Soft, weak, of coarse and open grain, pale yellow, 

 satiny, with thick, lighter colored sapwood. 



NOTES. A native of China, but naturalized in the United 

 States and planted frequently in southern Michigan as a foliage 

 tree. Only the pistillate trees should be planted, as these are 

 almost free from the objectionable odor of the staminate trees. 

 The smoke and dust of our large cities have little effect on the 

 foliage, and the trees are perfectly hardy in the southern part 

 of the state. 



171 



