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drained soil and seems to grow as fast in a loose clay soil as in a 

 black loam. When used for forest planting the spacing should be from 

 5x5 feet to 8x8 feet. The spacing should be governed by the quality 

 of the soil, and the amount of pruning that can be done. The locust 

 has the habit of having the terminal to end in a fork and having one 

 or more very large side branches. The best management requires 

 that the very large side branches be removed as soon as they are noted, 

 and one part of the terminal forks be cut off. 



The locust until recently gave great promise of being an important 

 tree for planting sterile, washed and eroded slopes, on which it usually 

 thrives and in many cases grows thriftily. However, reports from all 

 parts of the State show that locust groves wherever planted are being 

 killed by the locust body borer. The locust has also been attacked by 

 the twig borer, bag worm and the leaf miner. At present there are no 

 known economic means of controlling these destructive pests, and until 

 they can be controlled, the planting of locust for commercial purposes 

 will not prove profitable. 



SIMARUBACEAE THE QUASSIA FAMILY. 

 AILANTHUS. TREE OF HEAVEN. 



Ailanthus altissima (Miller) Swingle. TREE OF HEAVEN. STINK 

 TREE. (Ailanthus glandulosa Desfontaines). Plate 110. Medium 

 sized trees with dark gray bark, thin, rough or fissured on old trees; 

 branchlets very robust; twigs smooth; leaves compound and very large, 

 especially on coppice shoots, usually about 4-6 dm. long, odd-pinnate, 

 arranged spirally on the branchlets; leaflets 13-41, ovate-oblong, acu- 

 minate, oblique at base, entire or with a few blunt teeth toward the base, 

 smooth or hairy when they unfold, becoming smooth at maturity, dark 

 green above, lighter beneath; flowers appear in June in large terminal 

 panicles, the staminate and pistillate on different trees; fruit maturing 

 in autumn, consists of many light brown, twisted and broadly-winged 

 samaras which are about 1 cm. wide and 4-5 cm. long. 



Distribution. A native of China. Introduced and spreading in 

 cities, and into fields and woods in the southern part of the State. 

 The most notable occurrence is in Jefferson County on the wooded 

 bluffs of the Ohio River between Madison and Hanover. 



Remarks. Where the sugar and black maple can not be used for 

 shade tree planting this tree should receive attention. It adapts itself to 

 all kinds of soils, and to all kinds of growing conditions such as smoke, 

 etc. The crown is of an oval or rounded type. It stands pruning and 

 injury to trunk or branches quite well. It is practically free from 



