The genus Cortinarius; a preliminary study 



Calvin Henry Kauffman 



1 



Introduction 



The genus Cortinarius^ the largest genus of the Agaricaceae^ is 

 of special interest because of the small amount of work done on 

 it, especially in this country. Fries in Europe and Peck in Amer- 

 ica have described nearly all the species so far reported. In recent 

 years, Britzelmayr * has published a number of descriptions of 

 plants found in Bavaria, Germany, where the genus seems to be 

 well represented. That few students study the genus seriously is 

 perhaps due to the fact that it presents certain peculiar difficulties. 

 These, although great enough, are not more than those found in 

 some other parts of the mycological field. Saccardo seems to think 

 that the changing colors deter mycologists from paying more at- 

 tention to the group. The fading of the colors almost immedi- 

 ately after maturity is certainly a troublesome factor for the 

 beginner, and makes it less easy for him to progress rapidly in 

 their study. For these reasons it is necessary, first of all, to make 

 a thorough acquaintance with the various forms as they occur In 

 their native haunts. By repeatedly collecting the same species in 

 the same localities as well as elsewhere, one should be able at last 

 to distinguish even closely related forms. In this way, the writer 

 has succeeded, as he hopes, in making some small progress 

 towards a better knowledge of the genus. 



Three successive summers were spent in collecting material, 

 special attention being paid to the habitat and variabilities of the 

 different species. The same places were visited year after year, 

 and in this way duplicates of the same species from the same spot 

 were frequently obtained. The work was done at Cornell Univer- 

 sity, Ithaca, N. Y., and the rich collecting grounds in its vicinity 

 afforded abundant material. The fine collection of colored plates 

 of European species found in the botanical laboratory made pos- 



* 



Hymenomyceten aus Siidbayern. 



301 



