236 ILLINOIS ACADEMY OF SCIENCE 



varies with the elevation, the red oaks increasing in 

 number and the herbaceous vegetation becoming more 

 xerophytic on the higher ground. An area of this type 

 is located south of Central Street and east of Ridge Ave- 

 nue. Here the trees are Quercus bicolor, red oaks, elms 

 and ashes, and the undergrowth, Viola, Podophyllum, 

 Fragaria, Potentilla, Allium, Smilacina and Trillium 

 recurvatum. 



Where the ground is lower the swamp forest reaches 

 its climax. The most characteristic patch of this type 

 lies between Colfax and Grant Streets and Bennett and 

 Ewing Avenues in Evanston. This is called the ''Lin- 

 coln Woods" and is now a part of the Cook County For- 

 est Preserve. Other areas in which the forest is best pre- 

 served are in W^ilmette near the Electric R. R. between 

 Maple and Linden Avenues and at Chestnut Avenue 

 between Tenth and Eleventh Streets. Nearly (every- 

 where,) however, the forest trees have been left stand- 

 ing on vacant property and in yards and along the 

 streets. The herbaceous vegetation is also well pre- 

 served. 



An interesting patch of swamp forest is located at the 

 west side of Naiizig Avenue at the end of Isabella Street 

 where Iris and Caltha palustris are found under red and 

 bur oaks, Tilia, Crategns and Populus tremuloides. Iris 

 was found in several other places in depressions and in 

 shallow drainage ditches along the edge of the forest. 

 Caltha was not found elsewhere although it was reported 

 from the patch north of Winnetka Avenue, east of the 

 New Trier High School. 



AVhere the forest has been opened up or cut over and 

 unused, Salix, Populus tremuloides, Comus stolonifera 

 and Crataegus appear. A typical growth is to be seen on 

 Sheridan Road northwest of Winnetka Avenue. 



The slopes of the Lake bluff are covered with 

 Populus deltoides, Salix, Alnus incana and Rhus. At 

 the foot of North Avenue Winnetka, a small clump of 

 Juniperus communis has taken a foot-hold half way down 

 the slope. This has probably been imported from the 

 Waukegan region where it is common, as has the patch 



