Juncus marginatus and its Varieties. 125 



Texas: Drummond, F. Lindheimer, No. 193, 1843; Corpus Christi, H. 



W. Ravenel, April 30, 1869; Houston, Elihu Hall, PI. Tex. No. 657, 



April 20, 1872. 



Arkansas: Little Rock, F. L. Harvey, June, 1880. 

 Louisiana: Port Eads, on ballast ground, A. B. Langlois, May 6, 1885. 

 Mexico : Near Morales, San Luis Potosi, J. G. Schaffner, No. 500, 1876 ; 



Rio Blanco, Jalisco, Edward Palmer, No. 13, June 8, 1886. 



The considerations which have led to the disposition of the 

 species formulated above may be given in sufficient detail to 

 aid the future student who goes over the same ground. 



The type specimen of Juncus marginatus, which is probably at 

 Berlin, it has not been possible to consult, but Rostkovius's ex- 

 cellent figure, as well as his description of the plant, " cidmus 

 erectus pedalis vel sesquipedalis," " corymbus terminalis simplex" 

 and " capitv.la octo- vel decemflora" besides the type locality, Penn- 

 sylvania, leave no doubt as to the identity of the type form. 

 The type specimen of Juncus cylindricus, a fragment of which I 

 have been able to examine in the Engelmann herbarium, bears 

 heads with abnormally elongated axes and many flowers. It 

 belongs clearly to some form of Juncus marginatus, probably to 

 the type form. Dr. Engelmann, following a practice in com- 

 mon European use, gave to what he considered the type form a 

 varietal name, vulgar is, which, by reference to No. 33 of his 

 Herbarium Normale, is seen clearly to be identical with Rost- 

 kovius's plant. An examination of the type specimen of Juncus 

 marginatus paucicapitatas in the Engelmann herbarium shows 

 that it belongs to the type form of Juncus marginatus, and indeed 

 closely resembles Rostkovius's original figure of the species. 



The plant for which the name Juncus marginatus aristulatus is 

 here adopted has been known currently as Juncus marginatus 

 biflorus. Michaux's Juncus aristulatus has been referred by vari- 

 ous authors to Juncus marginatus without particular comparison 

 with any of its forms, but an examination of his description 

 leaves no doubt regarding the plant he was describing, for in 

 the expression " glomerulis triftoris " he names the most con- 

 spicuous external feature of this variety. Persoon's specific name 

 aristatus is an error for aristulatus, for Persoon cited Michaux as 

 the author of the name, with reference to the page of publica- 

 tion, and quoted his description with but slight changes. Re- 

 garding Juncus biflorus, it should be said that Elliott included 

 in his book descriptions of two plants of the marginatus group, 



