13 



our plants do not have accepted common names and I have left these 

 without them. 



In the writing of the manuscript an effort has been made to conform to 

 some supreme rule. In spelling and in the use of the hyphen Webster's New 

 International Dictionary, latest edition has been followed with few ex- 

 ceptions. Since there is no universally accepted standard of colors, al- 

 though Ridgway's "Color standards and color nomenclature" is used by 

 mammalogists, ornithologists, and some botanists, and since color terms 

 have been loosely used by authors to convey color concepts, I believe it is in 

 the interest of uniformity to delete all hyphens between color terms because 

 they add nothing to clarify the concept, except where used by Ridgway 

 when they represent a definite color. The "Style Manual of the United 

 States Government Printing Office," 1935, edition has been followed with 

 few exceptions. The outstanding innovation is the omission of the period 

 after abbreviations used in the metric system. The exception is that while 

 this authority does not begin proper names of specific and subspecific names 

 with a capital letter, I am following the International Botanical Rules and 

 I am using capital letters. I wish to go on record as vigorously opposing 

 the practice of decapitalizing specific or subspecific names derived from 

 proper nouns. Biological Abstracts has been followed in the matter of 

 abbreviating and listing bibliographic data. 



The keys and how to use them.— The key to the families has been 

 copied with a few changes from Robinson & Fernald's Gray's Manual, 

 edition 7, published in 1908 and adapted to the species which occur in 

 Indiana. The reason that I have adopted this key is that I have used it 

 since its publication and I have found it satisfactory. Other botanists with 

 whom I have conferred upon this subject all agree that the key is all 

 that is to be desired. I wish to express my thanks for the privilege of using 

 it. Keys to genera and species, except those of the parts contributed by 

 others, I have written myself and they are all artificial. 



A general key is given to assist the student in learning to which family 

 an unknown plant belongs. It is arranged in pairs of leads. The second 

 lead of a pair repeats the data given in the first lead but in a negative 

 form. Each succeeding set of leads is placed 2 spaces to the right and 

 some of the sets are preceded by a pair of letters to make them more easily 

 located, especially when one of the pair is very far from the other with 

 many intervening leads. 



To name a plant, read the first lead. If it fits your plant, proceed to the 

 next set of leads. If it fits the first lead of this set, proceed to succeeding 

 leads until it leads to a family or genus. If it does not fit a lead, try the 

 opposing lead. If it fits, proceed to the first part of the next set of leads. 

 Accept or reject leads until the key leads to a family or genus. The task 

 is not as easy as it may seem. After you have followed the key to a family 

 you may find the plant does not fit the family. Then you must retrace 

 the steps taken and be more careful to be sure the terms are understood. 

 Errors are usually the result of haste, misunderstanding of terms used, 

 or of poor or inadequate material for naming. The key may call for a 



