40 ILLINOIS NATURAL HISTORY SURVEY CIRCULAR 51 



used extensively in street, lawn, and group plantings. As speci- 

 men trees, they usually develop round tops. Blue and green ash 

 grow to a height of 60 feet, while white ash may reach a height 

 of 80 feet. 



The 8- to 12-inch-long, thin, compound, opposite leaves (Fig. 



41 inset) of these five ash species are composed of 5-11 egg- 

 shaped to elongate leaflets. They measure 3-6 inches long and 

 vary in color from light yellow-green to dark green according 

 to species. The leaves turn yellow to deep purple in autumn. On 

 white and green ash, the inconspicuous male and female flowers 

 are produced on separate trees. The paddle-shaped, winged seeds 

 are produced in clusters. The bark is thick, dark brown, and 

 deeply fissured with rounded, scaly ridges on white ash; red 

 tinted to brown and slightly furrowed and scaly on green ash ; 

 and thin, light gray, and broken into large plates on blue ash. 

 The hard, close-grained wood of some ash species, especially 

 white ash, is tough and strong, and it is used for tool handles, 

 oars, and sporting and athletic goods. 



Ash is subject to attack by some insects and diseases. It is 

 occasionally attacked by the fall webworm and green ash is espe- 

 cially subject to injury from oystershell scale. Also trees weak- 

 ened from growing under adverse conditions may be killed by 

 borers. In recent years many ash trees have died from what 

 seems to be a disease of unknown origin. Affected trees show 

 gradual dying back of branches followed by death of the trees in 

 several years. 



Bald Cypress 



This tree {Taxodium distichum) (Fig. 42) grows tall and 

 straight, reaching a height of 150 feet. Although it is a native 

 tree in the swampy river bottoms of extreme southern Illinois, it 

 will grow throughout the state and in many soil types. It grows 

 rapidly and is useful for ornamental purposes. It is resistant to 

 injury by ice and wind. 



The leaves (Fig. 42 inset) measure lA-% inch long and are 

 produced in a feather-like fashion on two sides of the small 

 branchlets. These branchlets with the leaves still attached drop 

 off in autumn. The long, drooping clusters of male flowers and 

 the globe-shaped, green, scaly, female flowers are borne sep- 

 arately on the same branch, the female flowers at the end of the 

 branch. The fruit is a small, globe-shaped, woody cone which 

 consists of thick, irregular scales, measures about 1 inch in diam- 



