260 American Midland Naturalist Monograph No. 6 



northern United States and southwards in the mountains to North CaroHna. 



Not uncommon in the more mountainous portions of our region. Now known from 

 Bedford, Somerset, Fayette, Washington, Blair, Cambria, Clinton, Elk, Clarion, McKcan, 

 and Warren counties. Specimen figured: Allegheny Mts., August 17, 1875. B. H. Pat- 

 terson. 



19. Stereodon Bridel, Mitten 



Mainly dioicous: robust to quite slender, green to yellowish-green or 

 golden brown, lustrous: stems elongate, decumbent or ascending, rarely erect, 

 mostly non-stoloniferous, simple or divided, irregularly or rarely regularly pin- 

 nate, the shoots mostly with hooked or circinate ends; leaves entire or serrulate, 

 often apparently 2-seriate, in most species falcate-secund, non-decurrent or but 

 slightly so, rather concave, ovate- to cordate-lanceolate, acuminate to more or 

 less subulate-acuminate; costa short and double or none; leaf-cells narrowly 

 prosenchymatous, smooth en both sides (except S. molluscum) , the basal 

 mostly incrassate and porose, parenchymatous in the mostly somewhat excavate 

 angles; inner perichaetial leaves plicate, lance-subulate: seta long, drying 

 twisted; capsule cemuous to horizontal, rarely erect, oblong to cylindric, arcu- 

 ate or rarely straight, mostly smooth and annulate; lid convex-conic, umbonate 

 to apiculate, or sometimes short-rostrate. 



A large genus mainly confined to the temperate regions. Many authors 

 now include most of the species under Hypnum (See Brotherus and Grout). 



This genus makes up a large part of the mossy mantle over old logs, roots, 

 bases of trees, roots, and earth in our woods, particularly in the southwestern 

 counties. 



Key to the Species 



A. Leaves neither distinctly falcate nor secund B 



A. Leaves more or less distinctly falcate or secund C 



B. Leaves entire 9. S. H aidant anus 



B. Leaves distinctly serrulate, at least towards the apex S. nemorosus* 



C. Leaves usually distinctly entire D 



C. Leaves serrate to serrulate at least towards the apex F 



D. Usually distinctly and regularly pinnate 7. S. Patientiae 



D. Not distinctly regularly pinnate E 



E. Alar cells gradually enlarged, not sharply differentiated; p>erichaetial leaves plicate; 



capsule, when dry, curved, not plicate 8. S. pratensis 



E. Quadrate alar cells numerous, inflated ones few; jserichaetial leaves not plicate; cap- 

 sules unsymmetric 5. S. cupressiformis 



F. Alar cells strongly inflated M (see also l) 



F. Alar cells not much inflated, or, if so, very few in number; or none G 



G. Not regularly pinnate; leaves usually entire 



5. S. ciipressiformis (See also S. pratensis) 



G. Rather regularly pinnate; leaves serrate or serrulate, at least above H 



H. Capsule symmetric or nearly so; a few alar cells somewhat inflated I 



H. Capsule more or less curved or arcuate J 



"■•" S. nemorosus (Koch) Lindberg is a southern Appalachian species extending north 

 to Virginia. It might occur in the mountains of Fayette or Somerset counties. Once 

 reported in eastern Pennsylvania. 



