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PREFACE 



THE present work owes its origin to a long-felt need for 

 a comprehensive treatise devoted to the genus Habenaria 

 in North America. It was begun ten years ago in the form of 

 a card catalogue devoted to every species native of the United 

 States and Canada. As the work progressed the absolute neces- 

 sity of an acquaintance with types became apparent, and in 1905 

 an effort was made to consult all the material that had a bear- 

 ing on the subject. 



Visits were made to the foremost European herbaria, and 

 loans secured of all the large collections in the United States. 

 From my own herbarium a representative series of specimens 

 was selected for comparison with type material, and from this 

 series individuals were sought for which matched the types in 

 detail. This method not only necessitated close scrutiny of every 

 character, but rendered the specimen ultimately chosen excep- 

 tionally valuable for future reference. 



In addition to descriptive notes and suggestive sketches, a 

 clear photograph was made of specimens which promised to be 

 of service in the preparation of a monograph. In this work I was 

 assisted by R. G. Leavitt and A. A. Eaton. 



In the interpretation of species I have avoided the tendency 

 of some botanists to recognize subspecies as worthy of specific 

 rank. Many years of experience with cultivated orchids, during 

 which slight variations in structure or color were assiduously 

 sought for among thousands of individuals, has convinced me 

 that caution should be exercised in the segregation of species, 

 and that there is danger of rendering the whole structure of sys- 

 tematic botany unwieldy by an inordinate multiplication of 

 slightly differentiated species. Everyone who has paid close at- 



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