158 WiEGAND : A Revision of the Gexus Llstera 



It soon became apparent that a study must be made of the 

 Asiatic and European representati\-es of the genus before definite 

 conclusions could be reached re^rardinfr the nomenclature of the 



t>""""'*'fc> 



forms found in North America. These results arc included here 

 although, owing to the relativel}' poor facilities for the study of 

 foreign species at the writer's command, they may not be as com- 

 plete as could be desired. 



From a historical standpoint the principal events may be 

 summed up ni a very few words. The two European forms were 

 early recognized by Linnaeus, although they were referred to the 

 genus Ophrys, Fifty years later Z. convallarioidcsi, the next 

 species, was described by Swartz from America, and a few years 

 afterward the same one was renamed by Chamisso and Schlech- 

 tendal. In 1840 several more species were described b}' Lindley 

 but, with the exception of several synonyms, only one was Amer- 

 ican, the rest Asiatic. A Japanese species was disco\'ered by 

 Blume in 1858, and a Chinese species, L. pubcrula, by Maxlmo- 

 wicz In 1883. In recent years several new species have been 

 found In America. The first was the Z. borcalis of Morong from 

 the northern Rocky Mountain region. Several years later Small 

 described a new species from the Alleghany mountains ; and dur- 

 ing the past year a third and still more western species has been 

 separated by Piper. Besides the works of Linnaeus, Willdenow^ 

 and Lindley no comprehensiv^e monographs of the genus have 

 ever been written, and the species of North America especially 



have received no detailed treatment. 



The genus Listera^ although widely distributed over the tem- 



perate and arctic regions, is nevertheless a small one, and at the 

 present time only about a dozen species are known. Very Inter- 

 esting In this connection is the fact that the Individuals of each 

 species are always rare or local, seeming to seek onl}' the most 

 secluded nooks In our damp mossy woods and largest peat bogs. 

 The most widely distributed of all the species, and at the 

 same time the smallest flowered, is Z. cordata. It is, more- 

 over, the only one found throughout the temperate zone. First 

 described by Linnaeus under the name Ophrvs^ It was later one of 

 the species upon which Brown founded the genus Listcra, The 

 characters of the plants are so distinct and constant that but little 



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