PREFACE 



In making this list the aim has been to include all conifers and 

 flowering plants, both native and introduced, which grow without culti- 

 vation in Nebraska. The known range of each species in the state is 

 given, followed by a list of the localities from which it has been 

 reported. These localities are mostly based on specimens in the 

 herbarium of the University of Nebraska. 



The arrangement of the larger groups is that of Dr. C. E, Bessey 

 in his Synopsis of Plant Phyla. Within the families the order is 

 usually that of Britton's Manual. 



As this list contains no descriptions it should be used in connection 

 with a descriptive manual. For this purpose Britton's Manual of the 

 Flora of the Northern States and Canada is recommended as it is the 

 only one covering the entire state. It is published by Henry Holt and 

 Company, New York. 



Each group is preceded by analytical keys and at the beginning 

 of the book keys to the orders will be found. The aim has been to 

 make these as simple and non-technical qs possible. As the number 

 of plants treated is much smaller than in the larger manuals the keys 

 should be much easier to use. In order to make it easy to find the 

 descriptions, after the name has been found by the keys, the page in 

 Britton's Manual where the genus is treated is given after the name 

 of each genus, thus Bromus 148. 



Names of orders end in -ALES and of families in -ACEAE and may 

 thus be recognized without repeating order or family before each. 

 Synonyms are given where a different name is used than the one in 

 Britton's Manual or when a different name is used in the New Gray's 

 Manual. 



In the appendix some of the structures most commonly used to 

 -n. > distinguish flowering plants from each others will be described. It is 

 r^) hoped that will be more useful for beginners than a glossary of spe- 

 _4 cial terms. 



^^ I wish to express my thanks to Dr. C. E. Bessey for advice and 



assistance while doing the work; to Rev. J. M. Bates and Dr. H. Hape- 



•w'w.man for allowing me to examine their collections of Nebraska plants; 



•1 (4 to Dr. P. A. Rydberg for looking over part of the manuscript and mak- 



^;^ ing valuable suggestions; to :\Iiss Venus Pool for suggestions in mak- 



■= ing the keys to the grasses. 



N. F. PETERSEN. 

 ■^ Louisiana State University, 



^ September, 1911. 



