LESKEACEAE ' 203 



Plants growing in dense tufts on rocks, or on the ground, 

 in dry, open woods, especially in limestone regions; rather 

 dark green, or olive-green; not common; not yet found 

 fruiting in our range. 



Stems erect, usually regularly pinnately branched; stiff, 

 harsh to the touch, especially when dry. 



Leaves small, straight; sometimes not easily seen; closely 

 folded when dry; rather dark green, or olive-green; dull. 



Seta long. 



Capsule long-cylindrical, curved; mature in spring; not 

 yet found in our range. 



Operculum cone-shaped. 



Range, Greenland to Virginia, west to Alaska and the 

 Rocky Mountains; Europe; Asia. 



Thuidium abietinum (Dill., L.) Bryol. Eur. may be 

 distinguished by the erect, pinnate stems, the straight 

 leaves, dark dull green in color, and by the stif, harsh 

 feeling when dry. Other mosses with similar growth are 

 lighter in color and grow in wetter places {Ilelodium 

 lanatum, p. 206); or have curved leaves, also lighter 

 green (Ptilium, p. 230) ; or are more common and have 

 glossy leaves {Ilypnum, p. 229). It is also well to re- 

 member that T. abietinum occurs chiefly in limestone 

 countries. 



b 



Thuidium delicatulum (Dill, L.) Mitt, and Thuid- 

 ium recognitum (L., Hedw.) Lindb. are two of the 

 largest species, and arc found in most localities. 



