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 ot 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 ot 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 torest 

 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 

 davs and weeks before the trees have come into lull toliage and 



