12 



L Private herbarium of Marcus Lyon, Jr., South Bend, Indiana. 



M University of Minnesota, Minneapolis, Minnesota. 



MC Private herbarium of Scott McCoy, Indianapolis, Indiana. 



Mi University of Michigan, Ann Arbor, Michigan. 



MK Private herbarium of Madge McKee, Goodland, Indiana. 



Mo Missouri Botanical Garden, St. Louis, Missouri. 



Mvv Milwaukee Public Museum, Milwaukee, Wisconsin. 



X National Herbarium, Washington, D. C. 



XD. University of Notre Dame, Notre Dame, Indiana. 



XW Northwestern University, Evanston, Illinois. 



XV New York Botanical Garden, Bronx Park, New York. 



Oberlin College, Oberlin, Ohio. 



I' Purdue University, West Lafayette, Indiana. 



Pa University of Pennsylvania, Philadelphia, Pennsylvania. 



Ph Philadelphia Academy of Sciences, Philadelphia, Pennsylvania. 



Po Pomona College, Claremont, California. 



S Private herbarium of A. S. Slavin, Rochester, New York. 



Sw State College of Washington, Pullman, Washington. 



St Stanford University, Stanford University, California. 



T Private herbarium of R. M. Tryon, Jr., Chicago, Illinois. 



W Wabash College, Crawfordsville, Indiana. 



We Private herbarium of Paul Weatherwax, Bloomington, Indiana. 



Wi University of Wisconsin, Madison, Wisconsin. 



Botanical Descriptions. — The botanical descriptions have been drawn 

 almost exclusively from specimens I have collected because they have been 

 at hand. Technical terms have been avoided whenever possible and the 

 few found necessary to use are defined in a glossary. The measurements 

 in the keys have been taken from herbarium specimens and are given in 

 the metric system and those in the descriptive text are in English terms. 

 The frequent use of "more or less, usually, and generally" is objectionable 

 to some people but to me these expressions are the shortest, the most 

 definite, and most comprehensive way of expressing the wide limits of a 

 qualitative or quantitative character. The ampersand (&) is used be- 

 tween joint authors and joint collectors. 



Botanical names of native plants are printed in bold face type and are in 

 accordance with the International Rules of Botanical Nomenclature. When 

 the names given in Gray's Manual, edition 7 and Britton and Brown's, 

 Illustrated Flora edition 2 differ from those in the bold face type for the 

 same plant they are regarded as synonyms and are printed in italics. 

 Botanical names in the text are printed in italics. Botanical names of 

 introduced plants and common names are printed in SMALL capitals. 



The accented pronunciation of the botanical names is indicated as fol- 

 lows: the grave C) accent indicates the long English sound of the vowel, 

 and the acute ( ' ) accent indicates the short or otherwise modified sound. 



The use of the term "variety typica" to designate the typical form of a 

 species is limited to those species where I have found it used as such. 



The common names are those given as such in "Standardized Plant 

 Names," with few exceptions. In many instances I do not agree with this 

 authority but 1 believe it is in the best interest of uniformity for me to 

 accept the names given in the aforementioned work. In rare instances 

 I have given two common names and the reason for so doing. Many of 



