Mosses and Lichens 



The peristome is double, the outer teeth are long and linear or 

 lance-shaped, marked with many cross-bars internally, prominent 

 below; the inner membrane is divided above into keeled seg- 

 ments adherent to or free from the teeth, and separated by usually 

 two to five hair-like divisions (cilia) mostly with spurs attached 

 at intervals to the margin. 



The annulus is large, compound, and rolls back as the lid falls. 



There are 800 or more described species, one hundred and 

 thirty-two in North America. 



Leaves. 



Plant with sporo- 

 phyte. 



Male. 



Female. 

 B. argenteum. 



With lid. Without lid. 

 Spore -cases. 



The Silvery Bryum, Bryum argenteum, Linn. 



Habit and habitat. In green or silvery-white irregular cushions, 

 on exposed ground, roofs, pavements, burnt places and almost 

 everywhere except on trees. Very common. 



Name. The specific name refers to the colour. Latin argen- 

 teum, silvery. Johann Dillenius, a German botanist, called this 

 moss "Catkin-stemmed Silver Moss" from its resemblance to the 

 catkins of a poplar tree. 



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