146 HORTICULTURAL SOCIETY OF NEW YORK. 



areas. Nevertheless, leaving" ^everything but the arborescent flora 

 out of consideration, the difference is very slight, from the stand- 

 point of the great variation in soil, which will be seen later. 



For convenience sake the vegetation will be divided into 

 three groups : 



First. — Vegetation indigenous to the above described area. 

 Second. — A'^getation indigenous to the area, but introduced 

 from one formation to another. 



Third — Vegetation introduced to the region. 

 The greater variety is found on the alluvial soil, and some 

 species are found here of more than common interest. Espe- 

 cially is this true of the deciduous group, there being very little 

 dift'erence in the Conifers, all of the latter having been practi- 

 cally exterminated by the soft-coal smoke of the city of Chicago 

 where manufacturing has encroached upon adjacent territory. 

 Originally the same vegetation as now found in the southern bor- 

 der of the city extended along the present water-front of Chi- 

 cago as far as the northern part of the old city limits. 



Of those species indigenous to the Alluvial Formation that 

 will be discussed here are: 



Liriodendron Tulipifera. 

 Nyssa multiflora. 

 Nyssa sylvatica. 

 Sassafras officinale. 

 Fraxinus quadrangulata. 

 Sassafras is found for about three miles beyond the north- 

 ern limit of the Alluvial Deposit on the "Lake Border Morain." 



Fagus ferruginea is a native of both the eastern and west- 

 ern borders of Lake Michigan, but only two groves are found 

 on the "Lake Border Morain" in the State of Illinois, and also 

 sparsely found in the northern part of the Alluvial Formation on 

 the Michigan side within the limits of the area here discussed. 

 Farther north on both sides of the lake large groves of well- 

 developed trees exist. 



Of the Morain vegetation of interest here are : 

 Acer saccharinum, 

 Acer rubrum, 

 Prunus serotina, 



