110 



ILLINOIS NATURAL HISTORY SURVEY CIRCULAR 51 



Fig. 99.— The slow- 

 growing sweet gum is 

 conspicuous because of 

 its distinctive five- to 

 seven-pointed, star- 

 shaped leaves (inset). 

 These aromatic leaves 

 become brilliant yellow, 

 orange, red, and purple 

 in autumn. 



The hairy clusters of male flowers are 2-3 inches long. The 

 clusters of female flowers are produced in swinging, globe-shaped 

 heads. The hard, ball-like fruits, 1-1 V2 inches in diameter, may 

 be objectionable in lawns. They contain 1 o-inch-long, brown, res- 

 inous, winged seeds which are set free in autumn. The gray 

 trunk bark may show flaky ridges. 



Sweet gum is resistant to injury by ice and wind and it is 

 relatively free of diseases and insect pests in Illinois. However, 

 two diseases that kill sweet gum trees have been reported, one in 

 Alabama and one in Maryland. The heavy, hard, close-grained 

 wood of sweet gum is not very strong. However, it is used ex- 

 tensively in interior finishing because of the alternating streaks 

 of red and black and the fine texture of the wood. It is also used 

 as a substitute for walnut and mahogany in the manufacture of 

 furniture. 



Sycamore 



Sycamore {Platanns occidentalis) , also called buttonball and 

 buttonwood (Fig. 100), is native to Illinois. Although it prefers 

 moist, fertile bottomland, occasionally it is found growing on 



