170 



the forest types run about 15 per cent upland plain, 60 per cent 

 hills, and 25 per cent bottoms; but a more exact location of the 

 northern boundary would practically eliminate the upland plain 

 type. The existing forests are somewhat denser than in the 

 three regions previously noted, having about 900 cubic feet of 

 timber per acre. The commonest trees are Quercus velutina 

 (etc.), Q. alba (etc.), Hicoria spp., Liquidambar, Quercus palus- 

 tris, Q. stellata, Ulmus spp., Fagus, Fraxinus spp., Acer sacchari- 

 num, Nyssa uniflora, N. sylvatica, Liriodendron, Quercus mary- 

 landica, Acer Saccharum, and Quercus pagodaefolia. The per- 

 centage of oaks is about the same as in the first two regions. 

 In addition to the species indicated by the typography as being 

 more abundant here than in other parts of Illinois there should 

 be mentioned Pinus ECHiNATA,which is said to grow nowhere 

 else in the state, but is too scarce to enter into the statistics. 



In the coastal plain or Tertiary region, which in Illinois cor- 

 responds approximately with the three southernmost counties* 

 Hall and Ingall estimated the forest area at 31 per cent, which is 

 probably none too much. (The 1910 census gives 26.8 per cent 

 of the farm land wooded, but about one fourth of the afea is not 

 in farms, and if only as much as half of that was woods it would 

 bring the total forest up to the figure named.) About two thirds 

 of the existing forest is in bottoms and one third on hills, and the 

 average stand is the highest of all, 1373 cubic feet per acre. The 

 commonest trees seem to be Quercus velutina (etc.), Q. palustris, 

 Liquidambar, Quercus alba (etc.), Fagus, Ulmus spp., Nyssa 

 UNIFLORA, Hicoria . spp., Acer saccharinum, Fraxinus spp., 

 Taxodium distichum, Nyssa sylvatica, and Platanus occi- 

 dentalis. The oaks here make up only about 39 per cent of the 

 total. 



It seems from this report that in Illinois Juglans nigra, Popuhis 

 deltoides, Betula lenta, Quercus macrocarpa, Ulmus americana 

 Acer Saccharum, and Tilia americana are most abundant north- 

 ward, and Taxodium, Betula nigra, Fagus, Quercus stellata, 

 Q. marylandica, Q. palustris, Q. imbricaria, Liriodendron, Liqui- 

 dambar, and both species of Nyssa southward. The reasons are 

 probably chiefly climatic, but this will not hold for Fagus, unless 



