Vol. 27 





No. 10 



BULLETIN 



OF THE 



TORREY BOTANICAL CLUB 



OCTOBER 1900 



Juncus tenuis Willd. and some of its North American Allies 



By K. M. Wiegand 



Several years ago while working over the forms of Juncus oc- 



- 



curring in the flora about Ithaca, N. Y. f the writer was led to the 



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conclusion that there are really several good species included in 

 the tennis group instead of only one or two as most writers have 

 heretofore affirmed. Since that time many field notes have been 

 accumulated, and these together with the information derived from 

 a large series of herbarium specimens have led to the results pre- 

 sented in the present paper. 



Juncus tenuis and its allies maybe treated in either of two ways. 

 They may all be referred to one or two composite specific types as 

 has heretofore been done by most authors, including Buchenau in his 

 elaborate monograph of the genus ; or the composite types maybe 

 broken up into their component parts. The latter method seems 

 more proper since the lines of development are all quite distinct, 

 and the various forms really represent separate kinds of plants. 

 The endeavor has been to treat these forms as conservatively as 

 possible, admitting new species only when appearing quite distinct 

 and when represented by a sufficient number of specimens to 

 guarantee constancy of characters. This has led to the result that 

 in a few cases quite diverse forms are still united under one species. 

 Some of these quite likely will be raised to specific rank when more 

 material is available. 



The characters used, it will be seen, are in many cases quite 

 different from those commonly employed for the separation of 



►ecies of Juncus. 



[Issued 26 October.] 



Considerable stress has been placed upon the 



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