HELPFUL SUGGESTIONS 



If in doubt what true mosses are, see Introduction 

 p. I, or use the Prehminary Key, p. 39. 



When collecting mosses for determination it is neces- 

 sary to notice habitat, that is, the natural locahty of 

 the plants. They are found on the ground, on rocks, on 

 trees, on decaying wood, or in ponds and streams. In 

 spite of the fact that earth-covered rocks and rotting 

 logs in deep, moist woods offer practically the same 

 soil conditions as the ground, the mosses are divided 

 according to actual situation, for simplicity of arrange- 

 ment in the Keys. For instance, if a moss is found on 

 a rock that is covered with soil, it is placed under 

 ^'Plants growing on rocks"; or if a moss is found on a 

 piece of an old log broken off and lying on the ground, 

 it is placed under '' Plants growing on decaying wood." 

 Notice the way the plants are growing; whether the single 

 plants are growing apart from each other, or crowded 

 together, with the stems erect, forming tufts, rounded 

 cushions, or deep mats by prolonging their growth at 

 the tips, or whether the stems are prostrate and inter- 

 woven, forming thin mats by continuing their growth 

 horizontally. See chapter on "Habit and Manner of 

 Growth," p. 12. 



Care must be taken to gather whole plants and not 

 merely a part of the stems. To be sure the mosses are 



