JUN 28 194] Vorchased HG Niedler F% boo. 
PREFACE 
While as a student I was taking systematic botany under Doctor 
C. E. Bessey, he gave me a copy of Webber’s Catalogue of the Flora 
of Nebraska and suggested that there were quite a number of plants 
reported for the state of which there were no specimens in the her- 
barium collected in Nebraska. 
Soon after this I began checking over the state collection in the 
herbarium, intending to make a list of such plants. When I had 
worked at this for some time, Dr. Bessey suggested a revision of 
Webber’s list of flowering plants for a thesis and that keys be added 
to make it more useful. The first edition was an attempt to carry 
out these suggestions. 
In general the plan of the present edition is the same as the 
preceding except that the ferns and related plants have been in- 
cluded. This was rendered easier by the fact the fern material had 
recently been gone over carefully by Prof. J. T. Fitzpatrick for his 
Fern Flora of Nebraska, recently published in the American Fern 
Journal. 
The list is thus intended to include all ferns, conifers, and fiow- 
ering plants growing without cultivation in the state. The range in 
the state is given, followed by the localities from which it has been 
reported. These localities are mostly based on specimens in the 
University herbarium. 
In the arrangement of the larger groups I have followed the 
classification in Dr. Bessey’s Synopsis of Plant Phyla. Within the 
families the genera and species are usually arranged as in Britton’s 
Manual. As it was not considered practical to include descriptions, 
this list should be used in connection with a descriptive manual. 
For this purpose Britton’s or Gray’s manual or Britton’s and 
Brown’s Illustrated Flora may be used. Britton’s is more nearly 
complete for our western plants, while Gray’s has some very useful 
illustrations. All these use Engler’s system of classification and to 
facilitate cross reference the page in Britton’s manual where the 
genus is treated is given after each genus. 
Each group is preceded by analytical keys and in the beginning 
of the book is a general key and a key to the families of spring 
flowers. The latter is based largely on the key to the families in 
H, F. Bergman’s Flora of North Dakota. The aim has been to make 
all the keys as simple as possible. Some of the terms are defined in 
the glossary of special terms in the appendix. 
While working on the original list I was permitted to look over 
the collections of Rev. J. M. Bates and Dr. H. Hapeman. These are 
probably the most important private collection of plants in the state. 
In the revision of the Cyperacee I have largely followed the 
treatment of Rev. J. M. Bates in his Sedges of Nebraska, published 
in the University Studies some years ago. 
While making the revision I have used the herbarium and bot- 
any library, and have received valuable assistance and suggestions 
from members of the faculty of the Botany Department, especially 
from Drs. R. J. Pool and E. R. Walker, for which I am very thank- 
ful. I also wish to thank Dr. A. S. Hitcheock for calling my atten- 
tion to some mistakes in grasses in the first edition; my brother, 
P. H. Petersen, for assisting in preparing the copy; and Prof, J. T. 
Fitzpatrick for helping with the proof reading. 
N. F.. PETERSEN. 
Lincoln, Nebr., 1922. 
