FORESTRY SURVEY 253 



formis), bur oak (Qucrcus maerocarpa) and occasionally 

 a small proportion of hackberry (Celt is occidental is), 

 buckeye (Aesculus glabra) and mulberry (Morus rubra). 

 Small trees of hawthorn or thorn apple and wild crab are 

 usually present and if not too heavily grazed such shrubs 

 as gooseberry, elder, bladder nut, wahoo and prickly ash 

 are to be seen. In very few places within the limits of the 

 townships included in this report are the characteristic 

 herbaceous jjlants present since owing to the open stand 

 and the heavy grazing they have been replaced by pasture 

 grasses and herbs. 



2. Stream side forest. — Confined to the stream borders 

 and lower flood plains there is usually a collection of such 

 trees as the river willow (Salijc nigra), river maple (Acer 

 saccharinum), cottonwood (Populus deltoides) with 

 smaller willows and button bush (Cephalanthus occiden- 

 tal is) as undergrowth. This type is commonly confined to 

 a strip of no very great width along the stream margin or 

 to the site of former ox-bow lakes. It usually passes 

 rather quickly but with no very sharp line of demarcation 

 to the rich bottom forest previously described. The dis- 

 tinction usually made between the two types is that stands 

 composed principally of willow and river maple are re- 

 garded as belonging to the stream-border while walnut, 

 ash and basswood may be regarded as indicative of the 

 bottom forests. In the southern part of the state many 

 different trees appear in these and in the bottom land for- 

 ests. 



Distribution of Forests. 



As the relationship between soil and forest distribution 

 is nowhere more clearly manifest than in La Salle County 

 it has seemed fitting that this report should follow a sim- 

 ilar order to that employed in the field survey, that is, the 

 tracts of prairie soils were examined first and then those 

 areas in which soils of other types were found were in- 

 vestigated. Such a program pointed to the northwest 

 corner of the county as the most natural starting point. 

 The maps accompanying the report are arranged in the 

 same order, similar and adjacent townships being 

 grouped. It may be noted here that tree planting about 

 homesteads of a half acre or less is not regarded in deter- 



