FIELDBOOK OF ILLINOIS WILD FLOWERS 
own destruction at the same time that they prepare the way for 
other and more highly organized communities. These successor- 
groups finally reach such a high degree of perfection and stability 
that we speak of them as climax communities, which may 
endure for centuries with little or no change. 
The great plant communities of Illinois are its forests and 
grasslands, covering many square miles. Then there are smaller 
communities of its rivers, lakes and ponds, and also some of its 
rocks and open sandy plains. Since we lack room here to discuss 
them all, mention of a few of the most important must suffice. 
Perhaps the forests are most interesting because of the abundance 
and variety of plants they contain and the beautiful flowers 
which the trees shelter. 
Most of our forests are old. They have occupied their 
places for centuries. We can, however, still find some young 
ones in abandoned farms and pastures that are no longer grazed. 
There the trees are likely to be small, some of them mere shrubs 
like the sumachs, the thorn and crab apples. Then there are the 
aspens, the sassafras and the red cedars. All these need an 
abundance of sunlight, consequently their seedlings do not de- 
velop well in their own shade but give way to oaks, hickories 
and maples, and in the southern part of the state to beech and 
tulip. While these changes in the forest communities are going 
on—changes that require centuries to accomplish—the soils 
too are changing and eventually there develops a luxuriant 
climax forest on a rich climax soil. 
Forest flowers.—We may for the present disregard the trees 
and examine some of the other plant citizens in the forest 
community and see how they have solved their problems. Each 
forest community in the succession which has led to the climax 
has its own group of wild flowers, but the finest collection is 
found in the richest forests. There they form a seasonal suc- 
cession from early spring to late autumn. 
The early spring flowers have a good water supply, for the 
winter snows and spring rains have thoroughly moistened the 
soil. In order to get plenty of sunlight they have stored material 
in bulbs, roots and rootstocks so that the spring beauties, the 
bloodroots, the dogtooth violets, the Dutchman’s breeches, the 
harbinger of spring, the hepaticas, the blue phlox and their 
associates are able to expand their leaves and open their flowers 
days and weeks before the trees have come into full foliage and 
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