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CONTRIBUTIONS KKOM THE SHAW SCHOOL OF BOTANY. 

 So. 7. 



A C((talo(jii,e of tlie AiithopJnjfa and Pteridophyta of 

 Ames, Iowa. 



By A. S. Hitchcock. 



Read Oct. 30, 1S90. 

 INTRODUCTION. 



The following list is based upon collections made during the 

 years 1S82 to 1SS9. All the names are founded upon specimens 

 in my herbarium unless otherwise stated. A few specimens are 

 in the herbarium of the Agricultural College at Ames, while a 

 very few names, indicated in each instance, are admitted on good 

 authority without specimens. 



Considerable care has been taken in the identification of spe- 

 cies, and in doubtful cases the name has been omitted from the 

 list. As Aster^ Sa/ix, Potouwgctoii^ Carcx^ and Equisetum 

 have not been thoroughly worked up, there will doubtless be 

 many additions in these genera. In order that the names in dif- 

 ficult genera should be authentic, the specimens ha\"e been sub- 

 mitted to specialists, to whom I wish to acknowledge my obliga- 

 tions. Many grasses were sent to Dr. Vasey and Prof. Scribner ; 

 carices to Prof. L. H. Bailey ; Cypenis and Eleocharis to Dr. 

 Britton ; Euphorbia to Dr. Millspaugh ; Umbellifcrcc to Dr. 

 Coulter ; Fraxini/s and Crativgiis to Prof. Sargent ; roses to Dr. 

 Best ; miscellaneous specimens to Dr. Watson. 



Gray's Manual, sixth edition, has been followed for the names 

 and sequence of the orders, and, in most cases, of the genera. 

 The principle of using the earliest specific name has been adhered 

 to as closely as possible ; that is, commencing with Linnteus' 

 Species Plantarum, in 1753, the earliest specific name, in what- 

 ever genus first used, is retained, provided it does not result in 

 two species of the same name in one genus, or in the specific 



