ILLINOIS NATURAL HISTORY SURVEY MANUAL 1 



grow, with a few exceptions such as arrowleaf, seeds of which 

 have been found with germinating powers unimpaired after 

 soakmg at the bottom of a pond for seven years. Again, drift- 

 wood and other floating objects may harbor fruits and seeds, 

 and carry them great distances. 



It is superfluous to point out that animals play an important 

 part in the dissemination of edible fleshy fruits. They also aid 

 in the dispersal of seeds and fruits which are inedible.. Some of 

 the seeds contained in fleshy fruits are disseminated very 

 effectively because they are not digested as they pass through 

 the alimentary tract of birds and animals. The prickly fruits 

 of burdock may be carried over great distances on the fur of 

 various animals or the wool of sheep. The seeds of certain rushes 

 at the water's edge are so tiny that they may be carried from 

 one pond or lake to another, mixed with mud clinging to the 

 feet of wading birds. Ants disseminate such seeds as those of 

 bloodroot, wild ginger and false mermaid, which have oily or 

 albuminous appendages. The ants feed on these appendages 

 and often carry the seeds considerable distances. 



Man is an important agent of dissemination, as he scatter s 

 seeds and fruits much as other animals do. He is still more 

 important, however, for his means of travel and transportation. 

 Many kinds of seeds are carried on trains and some of them are 

 scattered along the right of way. For this reason a railroad 

 track is an excellent place to go flower hunting. One is almost 

 sure to find there a flora rich in number and variety of species. 



THE NAMES OF PLANTS 



In studying large numbers of objects it is always necessary 

 to classify them in some way. This is true whether the objects 

 are plants, insects, rocks, bank notes or birds. In classifying 

 plants, all those that are the same kind, as determined by their 

 having like characteristics of leaves, flowers, stems, etc., as we 

 have already discussed, are said to constitute a species. This is 

 the simplest group of individuals which have descended from 

 the same stock. All species that resemble one another in certain 

 fundamental respects are grouped into genera. Similar genera 

 are grouped into Jamilies., families into orders and the orders 

 into classes. The plants discussed in the following pages need be 

 grouped for our purpose no higher than families. The families 

 appear in this book in order from simple to complex structured, 



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