Polytrichum commune (COMMON HAIR-CAP Moss) 1 



A. Classification: 



Division II. Bryophyta (moss-plants). 

 Class II. Musci (mosses). 

 Order. Bryales. 

 Family. Polytrichaceae. 

 Genus. Polytrichum. 

 Species, commune. 



B. Habitat: 



i. Polytrichum commune is widely distributed, growing 

 in the soil in fields and woods. 



C. Naked-eye Characters: 



THE GAMETOPHYTE (THE "MOSS-PLANT") 



1. Note that there are two kinds of leafy "moss- 

 plants." The one having the cup-like tip is the 

 male or antheridial plant; the other, without the 

 cup-like tip, is the female, or archegonial plant. 

 Compare the average height of the mature male 

 and female plants. Do you find any outgrowth 

 from the tip of any of the archegonial plants? 



2. Are the moss-plants differentiated into root and 

 shoot? Is the shoot further differentiated? If 

 so, describe. 



3. Briefly describe the extent and ramifications of the 

 "root" system. Are these true roots, with root- 

 hairs? 



4. Briefly describe the arrangement of the leaves on 



1 With minor modification the outline here given for the study of the 

 moss will serve for species of Mnium, Funaria, or almost any other com- 

 mon moss. 



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