90 HOW TO KNOW THE MOSSES 



green. Fine branchlets, called flagella (Plate V, Fig. 

 2a), are often present and should be looked for at the 

 tips of the stems. They are erect, rather stiff in appear- 

 ance, sometimes numerous, and about the same size 

 and color as the leaves, although they themselves are 

 covered with very minute leaves. Care must be taken 

 not to mistake very young capsules or new leaves for 

 the flagella. The leaves are usually slightly curved and 

 more hair-like at the tips and the young capsule is 

 covered with the yellowish calyptra. D.flagellare when 

 fruited most closely resembles Dicranella heteromalla 

 var. orthocarpa (p. 85), as both have erect capsules. 

 See under that species for comparison. Sterile plants, 

 unless the flagella can be seen, may be mistaken for D. 

 fuscescens (p. 93), and both occur on decaying wood, 

 but D. flagellare is more frequent and has a wider range, 

 as D. fuscescens is found chiefly at a higher altitude. 

 It is safest always to name species only from fruited 

 specimens. 



There are three other Dicranums with erect capsules 

 that occur on living trees, but they are rare; Dicranum 

 montanum Hedw., Dicranum longifolium (Ehrh.) 

 Hedw., and Dicranum viride (Sull. & Lesq.) Lindb. 

 The fruit is very rare. 



Dicranum montanum is a very small species with 

 stems usually not more than }^ inch long, found on trees 

 and decaying logs. The leaves are shorter and more hair- 



