i6o HOW TO KNOW THE MOSSES 



40. POGONATUM Palis. (Po-gon-a-tum) 



A genus containing many species widely distributed, 

 only a few of which occur in the eastern United States. 

 Four are described here. Name derived from the 

 Greek for '^ beard," referring to the hairy calyptra. 



Plants growing on the ground, more or less scattered; 

 olive or dark green; in two species growing from a green sub- 

 stance, called protonema, covering the soil. 



Stems erect, mostly not branched, rarely forked; }i-2 

 inches long. 



Leaves long and narrow, stiff, opaque; somewhat spread- 

 ing when moist; erect and slightly incurved, or closely folded 

 when dry; only very few in number and not always easily 

 seen when the plants grow from the persistent protonema; 

 olive or dark green. 



Seta about i inch long; reddish. 



Capsule erect, cylindrical, symmetrical; yellowish- or red- 

 dish-brown; mature in autumn. A white disk-like mem- 

 brane across the mouth, as in Catharinaea and Polytrichum. 

 (Plate VII, Fig. 4.) 



Operculum more or less long-beaked. 



Calyptra covered with corn-colored hairs. 



a. Plants growing from persistent protonema, leaves few 



.... P. brevicaule. 

 .... P. brachyphyllum. 

 h. Plants not growing from persistent protonema, leaves 

 numerous .... 



P. capillare. 

 P. urnigerum. 



