VOL. VIII, PP. 121-128 DECEMBER 21, 1893 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON, 



JUNCUS MARGINATUS AND ITS VARIETIES* 

 BY FREDERICK VERNON COVILLE. 



Jancus marginatus has long been known as a species well dis- 

 tinguished from all others, but widely variable within its own 

 limits. Writers 011 American botany in the early part of the 

 present century gave different names to various forms of the 

 plant, and not until 1866, when Dr. Engelmann published the 

 first part of his Revision of the North American species of the 

 genus Juncus, were they comprehensively treated as forms of 

 Jancus marginatus. 



The examination of the literature of Juncus marginatus, to- 

 gether with a large series of specimens, has brought the writer 

 to separate the species into three forms, namely, Juncus mar- 

 ginatus (type form), Juncus marginatus aristulatus, and Juncus 

 marginatus setosus, which may be presented as follows : 



Juncus marginatus Rostk. 



Jancus marginatus Rostk. Monog. June. 38, t. 2, f. 3 (1801). 

 Type specimen from Pennsylvania. 



Juncus cylindricus Curtis, Amer. Journ. Sci. xliv. 83 (1843). 

 Type specimen from Lincolnton, North Carolina. 



Juncus marginatus vulgaris Engelm. Trans. St. Louis Acad. 

 ii. 455 (1866). Type locality not given. 



* Presented at a meeting of the Biological Society of Washington, De- 

 cember 2, 1893. 



19-Btor. Soc. WASH., VOT,. VIII, 1893. (121) 



