102 HOW TO KNOW THE MOSSES 



Leaves hair-like, hut short; erect or somewhat spreading 

 when moist; only shghtly twisted and more erect when dry; 

 usually bright green in the new growth, brown below. 



Seta not more than }4 inch long; yellowish or light reddish- 

 brown. 



Capsule erect, symmetrical, oval, very small; reddish- 

 brown; mature in summer. 



Operculum with a long oblique beak, not easily seen with- 

 out a lens. 



Range, Labrador to Alaska, south to California and 

 South Carolina; Europe; Asia; Africa. 



Hymenostylium curvirostre occurs chiefly 07i wet cliffs 

 in limestone regions. The plants often form a deep, 

 dense growth, conspicuously green for about one-quarter 

 of an inch, and then brown below. The fruit is some- 

 times abundant. If the capsule is examined under a 

 lens it will be seen that there is no peristome. See 

 Didymodon (p. 104). 



13. TORTELLA (C. Mull.) Limpr. (Tor-tel-la) 



A cosmopolitan genus containing many species. 

 Name derived from the Greek for '* twisted," referring 

 to the twisted teeth of the peristome. 



The two species occurring in our range are found on 

 earth, rocks, and roots of trees; not common; fruit 

 occasional. 



Plants crowded together; green or yellowish-green. 

 Leaves long and narrow; much crisped when dry; green or 

 yellowish-green. 



