POLYTRICHACEAE i6i 



a. 



Pogonatum brevicaule Brid. (P. tenue (Menz.) 

 E. G. B.) is common on moist clay banks and road- 

 sides in open woods. The leaves are olive or 

 dark green. The plants are scattered and 

 grow from a green substance, called proto- 

 nema, which forms a thin coating on the sur- 

 face of the soil. All mosses first start from 

 protonema, but it usually disappears when 

 the leaves are developed. In P. brevicaule Sind 

 P. brachyphyllum the protonema is persist- ^brevkl^ 

 ent and assists in nourishing the plants, as Caiyptra 

 the leaves are greatly reduced in number. The ^"^^""s^^- 

 stems are very short, and the leaves are so few and often so 

 closely folded that they are likely to be overlooked unless the 

 plants are thoroughly moistened and closely examined. 



Range, Nova Scotia to Alabama and west to Missouri. 



Pogonatum brachyphyllum (Michx.) Palis, occurs in 

 New Jersey and southward. It grows from persistent 

 protonema, and has olive, or dark -green leaves like P, 

 brevicaule, and cannot be distinguished from it without 

 microscopic examination. 



b. 



Pogonatum urnigerum (L.) Palis, and Pogonatum 

 capillare (Rich.) Brid. are found in mountainous re- 

 gions and occur in the northern part of both hemi- 



