Jennings: Manual of Mosses — 34. Brachytheciaceae 285 



of the urn; capsule castaneous, about 1-1.3 mm long, oblong to oblong-cylin- 

 dric, about 2-2.5:1, erect and symmetric or nearly so, thin-walled but with 

 collenchymatous exothecial cells, slightly constricted below the reddish rim 

 when dry and empty; annul us none; lid obliquely subulate-rostrate from a coni- 

 cal base, about as long as the urn; oeristome-teeth with an unusually distinct 

 and heavy divisural, cilia single and usually about half as long as the usually 

 entire segments, basal membrane reaching to about one-third the height of the 

 inner peristome; spores mature in late summer to fall. 



On base of usually living trees; in moist woods from southern New Eng- 

 land to Ohio and southwards to the Gulf States. Not yet found in our 

 region. 



Family 34. Brachytheciaceae 



Autiocous or dioicous; paraphyses filiform; antheridial cluster^ gemmiform; 

 archegonial clusters on very short, rooting branches: slender to robust: stem 

 with central strand, creeping to ascending, or rarely erect, often interruptedly 

 sloloniferous, fasciculately radiculose, mostly irregularly pinnate; branches 

 mostly acute, often flagelliform and rooting at the ends; leaves unistratose, 

 pluriseriate, erect-spreading or appressed, rarely homomallous, dimorphic in 

 the stoloniferous species; cordate-oblong to lance-ovate or lanceolate, acumi- 

 nate or rarely obtuse; costa mostly incomplete; median leaf-cells prosenchyma- 

 tous, elongate-rhomboid to linear-vermicular, smooth or rarely papillose 

 towards the upper end of the cell, the basal cells lax and often porose, the 

 alar usually differentiated, being quadrate, green or hyaline, sometimes in- 

 flated: seta elongate, often rough; capsule cernuous to horizontal, mostly 

 short, ovoid or oblong and dorsally gibbous, when dry and empty more or less 

 arcuate, rarely erect and symmetric, oval to oblong-cylindric, never pendent, 

 smooth; collum faint; exothecial cells collenchymatous; peristome hypnoid, 

 imp>erfecr in some species with capsules erect; teeth lance-subulate, mostly 

 strongly hygroscopic, basally confluent, yellow or orange to red-brown, with a 

 zigzag divisural, dorsally cross-striate, lamellae numerous and well-developed; 

 inner peristome mostly free, with a high basal membrane, carinate segments 

 which are lance-subulate, cilia mostly complete, rarely none or rudimentary; 

 lid conic, obtuse to acute, often long-rostrate; calyptra cucullate, early decidu- 

 ous, mostly glabrous. 



A large and cosmopolitan family on various substrata, containing about 20 

 genera with more than 500 species. 



Key to the Genera 



A. Capsule erect to suberect, and somewhat unsymmetric to symmetric; basal membrane 



mostly low H 



A. Capsule cernuus to horizontal, unsymmetric; basal membrane mostly high R 



B. Leaves mostly with several deep plications 2. Camptothecium 



B. Leaves not deeply plicate c 



C. Lid conic, sometimes acute; alar cells differentiated 4. BTachythecium 



C. Lid long-rostrate, alar cells few or none D 



D. Cells narrow, dorsally smooth E 



D. Cells oblong-rhomboid to rhomboid-hexagonal, those of the branch-leaves more or 



