332 A MANUAL OF MOSSES 



covered by a felt of reddish radicles : the stems often reach 

 a length of 10 cm., strong; the elongate-lanceolate leaves en- 

 tire, strongly plicate, marginally revolute, gradually and even- 

 ly narrowed to the slender apex, reaching usually over 3 mm. 

 long; median leaf-cells linear, the basal shorter with very thick 

 and porose walls, the alar broader and short-rectangular to 

 sub-quadrate but rather few in number and not forming a very 

 distinct auricle : seta smooth ; capsule cylindric, arcuate. 



In wet meadows, bogs, and swamps ; Europe, Asia, and 

 from Arctic America to northern United States. Occurs in 

 Eastern Pennsylvania but not yet reported in our region. 



3. BRACHYTHHCIUM Bryologia Europsea. 



Autoicotts or dioicous : slender to robust, mostly widely 

 and flatly cespitose, green or yellowish-green to whitish, 

 sometimes lustrous : stems creeping or procumbent, sometimes 

 more or less erect, thickly-leaved, irregularly divided, inter- 

 ruptedly pinnate, stolon-like at the apex; stem and branch- 

 leaves unlike, stem-leaves erect-spreading to spreading, more 

 or less concave, mostly plicate, narrowly lanceolate from a 

 narrowed, ovate or triangular-cordate and decurrent base, 

 acuminate, marginally plane, serrate all around or only towards 

 the apex, rarely entire ; costa simple, usually long but rarely 

 complete ; median leaf-cells narrow to moderately wide, 

 elongate-rhomboid to linear, smooth, the basal more lax, and 

 shorter, the alar quadrate to rectangular or oblong-hexagonal, 

 forming a rather indefinitely bounded group ; branch-leaves 

 mostly shorter, narrower, with a somewhat weaker costa; 

 inner perichsetial leaves slenderly and finely acuminate : seta 

 more or less long, smooth to rough ; capsule cernuous to hori- 

 zontal, rarely erect, mostly short-oval and dorsally gibbous, 

 rarely oblong-cylindric, slightly arcuate when dry and empty ; 

 usually annulate ; peristome-teeth strong, basally confluent, 

 dorsally cross-striate, apically papillate, thickly lamellate ; 

 inner peristome about the same length, yellow to orange, free, 

 with wide basal membrane, the segments broadly lanceolate, 

 long-acuminate, carinately split and often gaping, cilia com- 

 plete, nodose to appendiculate, rarely rudimentary or lacking ; 

 lid conic-convex, obtuse to acute ; calyptra glabrous. 



A genus of about 190 species, occurring on various sub- 

 strata, mostly confined to temperate regions ; in North America 

 about 55 species; at least 14 species in our region. 



Key to the Species. 



a. Seta smooth. b. 



a. Seta rough, at least in part. g. 



b. Annulus none, cilia rudimentary or none. 



c. 



b. Annulus often present; cilia well-developed. 



d. 



