THE POLYTRICHACE^E OF WESTERN NORTH AMERICA 297 



So named because the leaves are strongly twisted or contorted 

 when dry. 



Plants large, gregarious or loosely caespitose, glaucous green above, 

 brown below. Stems simple, or with an innovation from under the 

 perichetium, loosely and irregularly foliate its whole length. 



Leaves erect, open, twisted and crisped when dry, linear-lanceo- 

 late, usually longer upwards on the stem, acute, sheath scarcely 

 broader than blade. Margin sharply serrate to the base. Lamellae 

 20 40. Marginal cells of the lamellae oval, smooth, not very 

 much larger than the others. Vein percurrent, sparingly dentate on 

 the back. Perichaetial leaves similar to the foliage leaves. 



Calyptra covering the whole capsule. 



Capsule ovate to obovate or cylindric, erect or somewhat curved, 

 papillose, when dry slightly constricted under the mouth, without 

 stomates. Teeth 32. Lid convex, rostellate. Pedicel long, flexu- 

 ous. On soil, usually clay. Along the coast from the Alaska Penin- 

 sula to California; Rocky Mountains, at least of British Columbia. 



2. Pogonatum capillare (Rich.) Brid., in Bryol. Univ. II, p. 127, 



(1827). 

 Pogonatum dentatum Brid., in Bryol. Univ. II, pp. 122 and 744, 



(1827). 

 Pogonatum capillare var. dentatum Lindb., 15 in Act. Soc. sc. Fenn. 



1872, p. 266. 



Name derived from capillaris = hairy; probably referring to the 

 hairy calyptra, so common in this family. 



Plants 2.5 cm. high or less, gregarious or loosely caespitose, glauc- 

 ous green; male plants smaller. Stems slender, mostly simple, 

 loosely foliate, with rhizoids at base. 



15 Cardot and Theriot, in "Mosses of Alaska, " Proc. Wash. Acad. Sci. 4: 327 (1902) 

 say "Pogonatum dentatum (Menz.) Brid. is but a western race of P. capillare, charac- 

 terized by having slenderer stems than those of the type, and by its pedicel which is 

 usually not so flexuous. " This hardly seems sufficient difference for a variety. 

 Cloudy weather and wet soil cause stems to grow longer and more slender. The 

 northwest coast of North America is characteristically damp and cloudy. Potatoes 

 growing in a dark damp cellar are not called new varieties. Further the difference 

 is not constant. The marginal cells of the lamellae vary a great deal, so this dis- 

 tinction, shown in the figures in Sullivant's Icones Muscorum, does not hold. 



