DICRANACEAE 79 



a. Leaves too small to show outline; closely folded when dry; 

 a rather bright green. 



Seta usually less than i inch long; reddish-brown. 

 Capsule erect, cylindrical, slender; reddish-brown; 



mature in autumn. 

 Operculum short-beaked. D. tortile. 



D. vaginans. 



b. Leaves easily seen, long, hair-like, spreading; yellowish- 

 green. 



Seta usually i-i/4 inches long; yellowish. 



Capsule erect or slightly inclined, long, cylindrical; 



yellowish ; mature in June. 

 Operculum short-beaked. D. pallidum. 



Ditrichum tortile (Schrad.) Lindb. and Ditrichum 

 vaginans (Sull.) Hamp. are both found in the eastern 

 half of North America and in Europe, the former 

 also in Asia and Africa. They resemble each 

 other too closely for the beginner to identify 

 them easily. They grow on moist banks, often 

 along roadsides, very rarely on rocks. The 

 stem^s and capsules are very slender, and the 

 leaves are so small and so closely folded, es- ^'[['^llil^ 

 pecially when dry, that one is hardly con- capsuie 

 scious that there are any leaves at all, as ^"^^'■^^^• 

 the plants look as though they consisted of tiny 

 green stems with the fruit and fruit-stalks. No other 

 small mosses with small erect capsules are commonly 

 found on moist soil. Barbula (p. 105) has erect cap- 

 sules, but usually grows on drier soil, is less com- 



