INTRODUCTION. V- 



The two extremes of the State present vast differences in the 

 character of their vegetation, as might be expected from climata- 

 logical considerations alone ; but some of the most conspicuous 

 dissimilarities arise from causes quite independent of climate. The 

 southern third is for the most part heavily wooded, the northern 

 and central portions mostly prairie. At least, this was the normal 

 or original condition of things before the planting of orchards and 

 shade trees in the prairie districts, and the clearing of forests in 

 the wooded sections changed somewhat theii- relative proportions. 

 The change thus wrought has been in some respects very great ; 

 but it is asserted (and certainly with truth as regards some sec- 

 tions) that the conversion, by Nature's own hand — though through 

 the agency of civilized man by the stoppage of prairie fires — of 

 what were prairies fifty years ago into what are forests at the present 

 time, has very nearly, if not quite, balanced the extent of deforestation. 



The northern Coniferce are scarcely represented in the sylva of the 

 State, only six (out of ten species found in the Northern States) 

 occurring altogether, and nearly all of these solely in the northern 

 tier of counties, and there locally. Thus, of the pines, Pinus banks- 

 iana (gray pine) occurs in Cook and Ogle counties*, and P. strobus 

 (white pine) in Cook, Winnebago, and Ogle counties ; the larch {Larix 

 ajiiericana) in McHenry, Stephenson, and Winnebago counties, Juni- 

 perus sabina, var. procumbens, in Cook county, and the yew {Taxus 

 baccata, var. canaderuis) in Winnebago and Ogle counties ; the only 

 other one occurring in more than two counties being the arbor-vitae 

 {Thvja occidentalis), which has been found in Peoria, Cook and Kane 

 counties. Of the numerous southern and eastern species of Coniferce, 

 only four, or possibly five, occur in Illinois, as follows : The bald cy- 

 press {Taxodium distichum) in the inundated lands of the southern 

 part of the State ; the white cedar {Chamacyparis spihceroidea) in Gal- 

 latin county, and the yellow pine {Pimis mitis) on the rugged south- 

 ern hills. It is supposed that a fifth species, the Jersey scrub pine 

 {Pinus inops), probably occurs with the last species, since it is very 

 abundant on the "knobs" of southern Indiana. Two species of gen- 

 eral distribution, so far as the country at large is concerned, occur both 

 in the northern and southern portions, though they are more or less 

 local, and wanting, too, for the greater part of the State. These are the 

 red cedar {Juniperus virginiana) and common juniper {J. communis). 



* Probably in Lee county also (fide Professor Forbes, in epist.) 



