ILLINOIS TREES: SELECTION. PLANTING, AND CARE 



111 



Fig. 100.— The fast- 

 growing American syc- 

 amore has been planted 

 extensively in recent 

 years where elms have 

 died. Its maple-like 

 leaves (inset) are broad 

 and firm. 



^F 



J 



K" 



—1 



^r 



11 ^w* ~ 



^^L 



. 1 



4 



F 'HUkVvrB 



^M 





^a 



CVffHTcsl 



^p^s 



l^^^y 



^ 



^m 



b^^Mr^^HTT^EaCSjj 



BqHMQ^^b^BHE t 



^m 



^m 



^H^^^I^BP^w 



^^^ 



tf 



w BRESy^^BB 







P^^^^^^^TH^^^^H 





^^J^Il 



( 



pi 



Ps^ 



•-^ 1 



dry ridges or rock ledges, and it is grown extensively in dry, 

 upland soils. Sycamore and two introduced species, London plane 

 tree (P. acerifolia) (Fig. 101) and oriental plane tree (P. orien- 

 talis) , are used in shade, street, and ornamental plantings. They 

 are tolerant of drought as well as smoke and other adverse city 

 conditions. They grow rapidly, reaching heights of 70-100 feet, 

 with horizontal branches that have a spread of 50-75 feet. 



The large, thin, firm, broad-bladed, coarsely toothed, alter- 

 nate leaves (Fig. 100 and 101 insets) are 4-7 inches across, 

 bright green on top and pale beneath, with fine, conspicuous 

 hairs where the veins are attached to the midrib. Leaves of syca- 

 more and London plane tree have three to five sharp-toothed 

 lobes, and those of oriental plane tree have five to seven lobes. 

 The stout leaf stems are 3-5 inches long. The enlarged, hollow 

 base of each leaf stem encloses next year's bud. Male and female 

 flowers are borne separately on the same tree. Although both 

 types of flowers are inconspicuous, the fruits are globose, brown- 

 ish, prickly balls about 1 inch in diameter which hang from the 

 branches by long, slender, flexible stems 3-5 inches long. Usu- 

 ally there are two balls per stem on London plane tree, two to 



