14 



MOSSES WITH A HAND-LENS 



CERATODON 



CERATODON is one of the commonest of all our mosses. 

 It is found on the edges of paths, roofs of old buildings, 

 sand by the sea shore, and in general any barren compact 

 soil is its favorite habitat. The plants are short and grow close 



together, forming dense 

 thin mats of dark green. 

 The lance-like young 

 sporophytes appear 

 early in spring as soon 

 as the snow is melted. 

 By the middle of the 

 summer the capsules 

 often decay beyond 

 recognition and the 

 seta breaks from the 

 plant at the touch. 



Unless one has be- 

 come very familiar 

 with Ceratodon it is 

 not always easy to 

 recognize it without 

 mature capsules. When 

 the capsules have fully 

 matured they shrink 

 when dry and become furrowed. This peculiar furrowing and the 

 dark rich color of the capsules, a color called purple by the older 

 botanists but which is really a very dark chestnut or red-brown, 

 make it easy to recognize this species [Ceratodon purpkreus (L ) 

 Brid.] 



Gymnocybe has a capsule furrowed in a similar manner, but 

 it is easily distinguished by the characters noted under the de- 

 scription of that genus. 



Fig. q. Ceratodon purpurens X 2. 

 calyptra, and capsule X 10. 



Leaves, 



