31 



units large enough to crop. It is a type intermediate between the as- 

 sociation of the flood-plains of the large rivers and the upland types ; and 

 in general more nearly conforms to the sandy loam associations of the 

 upland hardwood type than to any other. Such characteristically bot- 

 tomland species as river birch, cottonwood, sycamore, and silver maple 

 are associated with such typically upland species as basswood, hard maple, 

 tulip-poplar, and red oak ; or certain species common to both bottomland 

 and upland, such as elm, hackberry, and honey locust, grow best on these 

 well-drained bottoms. Black walnut makes its best growth throughout 

 the state in this type. In the Ozark region, the species commonly found 

 on these bottoms are beech, hard maple, red gum, tulip, shagbark and 

 shellbark hickories, black and white walnuts, red and white oaks, white 

 elm, hackberry, sycamore, honey locust, Kentucky coffee-tree, black gum, 

 and white and green ash. About the same association occurs where such 

 bottoms are wooded in the counties bordering the Wabash River, al- 

 though pin oak becomes a common tree here. Along streams tributary 

 to the Big Muddy, Kaskaskia, Saline, and Little Wabash rivers, this type 

 has a higher percentage of the oaks. Pin and shingle oaks are the com- 

 monest trees, with white, cow, bur, and red oaks, and shagbark, bitternut, 

 and mocker-nut hickories of frequent occurrence, and black walnut, honey 

 loctist, hard maple, black cherry, river birch, and cottonwood occasional. 

 Red gum does not occur in the Kaskaskia region ; hard maple and bass- 

 wood are not common in either the Big Muddy or Kaskaskia basins ; and 

 tulip does not occur north of a line extending from southern Randolph 

 county on the Mississippi side to southern Williamson and Saline coun- 

 ties, thence up the Wabash to Vermilion county, and inland to eastern 

 Hamilton and Wayne counties. 



Throughout the central and northern parts of the state, the bottoms 

 along the secondary streams have appreciable quantities of elm. Near 

 the heads of streams just off the prairies, soft maple and elm often form 

 the entire stand ; but honey locust, box-elder, hard maple, river birch, 

 black and white walnuts ; bur, white, swamp white, and red oaks ; ash, 

 black cherry, Kentucky coft'ee-tree, and shagbark and bitternut hickories 

 may enter into the composition. Basswood, in some of these stands in 

 La Salle county, makes up a high proportion of the forest and is a com- 

 moner tree in the northern than in the southern part of the state. Hick- 

 ory forms nearly pure stands on the bottoms along Bear Creek, Hancock 

 county. It is doubtful if beech occurs native anywhere in the central or 

 northern part of the state north of Vermilion county, with the exception 

 of a very few trees in Lake and Ogle counties. 



A representation of species by per cents based on 14.4 acres of 

 samples from the northern, central, and southern regions shows hard 

 maple, 19; ash, 18; black oak, 17; white oak, 15; elm, 10; black walnut, 

 5 ; hickory, 4 ; basswood, 3 ; beech, 2 ; tulip, 2 ; cherry, 1 ; and black gum, 

 honey locust, and Kentucky coffee-tree aggregating 2. Ash, black wal- 

 nut, and hard maple occur more frequently in this type than in any other. 



