10 



The present flora is an attempt to bring up to date our knowledge of 

 the ferns, fern allies, and flowering plants of Indiana. It became neces- 

 sary to adopt a rule or standard by which a species could be admitted 

 or excluded from the flora, and it was decided to admit only those species 

 which have one or more herbarium specimens to verify their occurrence. 

 An exception has been made in the case of Adlumia fungosa which I saw 

 in a woods in La Porte County. Doubtless a few species have been ex- 

 cluded that do occur in the state. I refer specifically to Podostemum 

 ceratophyllum and Elatine minima which have been reported and have 

 Indiana within their general range. I have, however, made strenuous 

 but unsuccessful efforts to find specimens of both these species. I have 

 admitted a few species where I have seen no specimen but the evidence 

 for their existence in Indiana is convincing. 



My study has been made primarily from specimens in my own her- 

 barium which numbers more than 65,000 sheets, more than 47,000 of 

 which are from Indiana. In addition I have examined all the Indiana 

 specimens in all of the other Indiana herbaria which total 36,936 sheets 

 but these were studied only sufficiently to check the identification. The 

 keys and measurements have been made from my own specimens. The 

 ecological notes have been taken also from my specimens. 



No effort or expense has been spared to have my specimens named 

 correctly. In order that specimens belonging to critical genera be au- 

 thentically named, I have sent them to specialists to be determined or to 

 have my identifications verified. I wish here to express my sincere ap- 

 preciation to the following persons who have examined my specimens in 

 the groups upon which they are authorities : L. H. Bailey for Rubus and 

 Vitis; C. R. Ball for Salix; J. H. Barnhart for Utricidariaceae; Ezra 

 Brainerd (deceased) for Viola; Agnes Chase and A. S. Hitchcock (de- 

 ceased) for Gramineae; H. S. Conard for Nymphaeaceae; Carl Epling 

 for Labiatae in part ; M. L. Fernald for Potamogeton and various species ; 

 Ray C. Friesner for Solidago; Frederick J. Hermann for Carex and 

 Juncaceae; Lawrence E. Hicks for Lemnaceae; Milton S. Hopkins for 

 Arabis in part; Theodor Just for Chenopodiaceae; Rogers McVaugh for 

 Lobelia; P. A. Munz for Onograceae in part; E. J. Palmer for Crataegus 

 and miscellaneous species; Francis W. Pennell for Scrophulariaceae; 

 Rosendahl, Butters, and Lakela for Heuchera and Sidlivantia; Paul 

 Standley for Houstonia in part; E. E. Watson (deceased) for Helianthus; 

 C. A. Weatherby for assistance for many years on ferns ; Louis C. 

 Wheeler for Euphorbia; Edgar T. Wherry for Polemoniaceae; K. M. 

 Wiegand for Amelanchier and Oxalidaceae; and T. G. Yuncker for 

 Cuscuta. I wish here to thank all others who named or checked over 

 small groups or who loaned me Indiana specimens for study. 



Distribution of Indiana Plants. — The general distribution of a species 

 is given in a closing paragraph after the discussion of the species. The 

 state distribution is shown by a map. Published records that do not cite 

 specimens are omitted but sometimes one or more may be discussed. 

 Some more or less complete county floras have been published without 



