Vol. 26 



No. 4 



BULLETIN 



OF THE 



TORREY BOTANICAL CLUB 



t. 



APRIL 1S99 



A Revision of the Genus Listera 



Rv Karl M. \ViF:GANn 



(Plates 356, 357) 



Few genera of North American plants in which the species 

 are distinct, and licnce not difficult to understand, have been so 

 neglected as has the genus Listera. During the past k^ years, 

 however, several new species have been discovered, so that only 

 one remains to be described as new in this paper. Still the known 

 facts are so scattered and some of the .species are so little understood 

 that the present paper has been prepared with the attempt to 

 illustrate and describe each species very fully, besides providing 

 an analytical key for easy identification. 



• The genus has proved to be a very pleasant one upon which 

 to work, owing to the distinct character of the species, and the 

 confusion heretofore existing can be attributed only to the diffi- 

 culty of recognizing types from the old descriptions. In addition 

 to this the local and restricted distribution of all the species tended 

 to make the solution still more difficult. 



Few more interesting examples of the misinterpretation of 

 specific types arc encountered than those met with in the treat- 

 ment by different authors of the western members of the conval- 

 larioidcs group. As a result of this, although numerous attempts 

 were made to describe forms which even by the older authors 

 were , recognized as clearly distinct, until recently only one 

 species really received a tenable name. 



[Issued 12 April, 1899.] ( 157 ) 



