i66 HOW TO KNOW THE MOSSES 



num from P. commune with a capsule almost cubic, 

 and from P. ohioense with a capsule tapering at the 

 base. See also the following species. A peculiar annual 

 growth sometimes occurring in the male plants is 

 described under P. commune. See Plate VII, Fig la. 



Polytrichum strictum Banks, is found in peat-bogs 

 and moist woods, especially in the higher altitudes. 

 The typical form is not common, although gradations 

 between the type and P. juniperinum are more fre- 

 quently collected. Typically the stems are over j inches 

 long, slender, and covered for a great part of their length 

 with a thick mass of whitish radicles. The leaves are 

 dull green or olive, shorter than in most of the other 

 Polytrichums, more erect when moist and more closely 

 folded when dry, so that the leaves have to be bent back 

 to see the folded margins. The capsule is sharply four- 

 angled, very little longer than broad. 



Range, Arctic America, Canada, and the northern 

 United States; Europe; Asia; South America. 



The very slender stems of Polytrichum strictum 

 matted together with whitish radicles, and the closely 

 folded leaves, are usually very noticeable, but the 

 gradating forms are sometimes difficult to distinguish 

 from P. juniperinum. P. juniperinum may be ex- 

 pected in drier localities and is a more common 

 species, with less slender stems and leaves more spread- 

 ing when moist. 



