THE SELAGINELLA RUPESTRIS 

 GROUP. 



botanists consider 

 that the shape, size, 

 and arrangement of the 

 leaves of Selaginella are 

 of sufficient importance 

 to warrant the separa- 

 tion of this genus into 

 four sub-genera. The first of these is called Euselaginella 

 and contains, those species with leaves all alike and ar- 

 ranged in many rows. From the fact that the common 

 species in eastern North America are typical of this 

 group, they are often spoken of as the Selaginella ru- 

 pestris group. Although here called the true selagi- 

 nellas they are relatively few in number, probably 

 less than twenty-five in all, though distributed very 

 widely over the earth. 



'The Rock Selaginella. 



The student of the mosses is likely to be better 

 acquainted with the haunts of the rock selaginella, 

 ( Selaginella rupestris } than the student of the fern 

 allies himself, for it is a species of the dry ledges 

 and mossy boulders, growing in situations shunned by 



