HOW TO USE THE FAMILY KEYS. 43 



final product of the weed — the one object of its existence — enough 

 has been said or will be said in the pages which are to follow. Hav- 

 ing thus described the parts of a weed we see that while they are 

 numerous they are not difficult to learn. Anyone with a corn 

 cockle or some other weed by his side can soon learn these parts 

 so that he should be able, with the aid of the family keys and de- 

 scriptions which follow, to locate any one of the 150 weeds which 

 are listed. Only a little time, a little patience, a little labor are 

 necessary and a knowledge which will open up a new world of value 

 and of interest will be his. 



Keys to Families of Weeds. 



Weeds which have a number of different characters in common 

 are grouped into a family by themselves. The 227 species of In- 

 diana weeds hereafter considered belong to no less than 38 dif- 

 ferent families. Each of these families has both a common and a 

 scientific name. Keys or tables leading up to each family have 

 been prepared. A person by aid of these keys can locate the weed 

 at hand in its proper family and then, by comparing the descrip- 

 tions of the weeds grouped under that family heading with the 

 one in hand, will soon be able to tell whether it is one of the de- 

 scribed and listed species or not. It must be remembered that 

 there are other plants, 1,800 and more, growing wild in Indiana 

 which are not described in this book and it is, therefore, very prob- 

 able that one of them may be the supposed weed which the per- 

 son is trying to locate. If so, he may or may not be able to locate 

 it in the family to which it belongs, by the keys given, for those 

 keys are designed only for the species of weeds listed and there are 

 manj r other families of plants besides those including the weeds 

 which are represented in the State. 



How to use the kf.y. — Gather a complete specimen of the sup- 

 posed weed, roots and all. Be sure and get one in flower and if pos- 

 sible also partly in fruit. Have a pocket lens or magnifying glass, 

 such as a linen tester, a sharp pocket knife and a long needle at 

 hand. First examine the leaves and a cross section of the stem to 

 see whether it is an endogen or exogen. (Fig. 15.) If an endogen, 

 go to the "Key to the Families of Endogen Weeds" and compare 

 carefully the plant with the characters mentioned after a. If it 

 agrees with these go to h and compare with the characters there 

 given ; if it does not fit them, go to hi and again compare. If it 

 fits b or hi go to the family whose name and page are given after 

 the letter it fits, and read over the family description carefully to 



