46 American Midland Naturalist Monograph No. 6 



L. Stereid bands above and below the guide-cells; peristome teeth separate to below 



the mouth of the capsule 11. Dicranodontium 



M. Alar cells not definitely inflated Brolhera 



M. Inflated alar cells reaching the costa 10. Dicranum longifolium 



N. Basal leaf-cells short-rectangular; the capsules sulcate 5. Ceratodon 



N. Basal leaf-cells somewhat elongated-rectangular O 



O. Capsules, when dry, sulcate 4. Ditrichum pallidum 



O. Capsues not sulcate when dry 4. Ditrichum pnsillum and D. lineare 



P. Peristome teeth divided one-half way down or more 9. Oncophorus Wahlenbcrgii 



P. Peristome teeth not divided 8. Rhabdoweisia 



Q. Cleistocarpous t 1. Bruchia 



Q. With peristome {Oreoweisia) * 



I. Bruchia Schwaegrichen 



Autoicous or paroicous; gregarious: green protonema persistent but sparse; 

 stem short with a central strand; leaves long-canaHculate-subuIate, from an 

 oval to lanceolate base, erect to secund; costa broad and flat, filling the subulate 

 acumen; laminal cells rectangular; seta short; capsule pyriform, more or less 

 cernuous, rostrate; operculum none; calyptra covering one-third or more of the 

 capsule, mitrate, unsymmetrically cleft. 



A widely distributed genus of about 25 species, 14 of these being found in 

 North America, one already found and another probably occurring in our 

 region. 



Key to the Species 



A. Collum less than one-half the whole length of capsule; seta usually longer than 



capsule 1. B. ftcxuosa 



A. Collum about as long as rest of capsule; seta usually shorter than capsule 



2. B. Sullivantii 



1. Bruchia flexuosa (Swartz) Mueller 



Gregarious, the green protenema persistent but not very conspicuous: stems 

 about 2-4 mm long, curved to erect; leaves remote, small, lance-subulate, erect- 

 spreading from a concave base, somewhat serrulate at the apex; leaf-cells 

 rectangular, narrower at the margin, alar not much different; antheridia in 

 axils of comal leaves or in separate buds; seta short, stout, usually shorter than 

 the erect, ovoid-pyriform, partially exserted, apiculate capsule; calyptra nar- 

 rowly conic, mitrate; spores .030-. 040 mm in diameter, decidedly papillose, 

 mature about June. 



This and the following species perhaps differ too little to be regarded as 

 distinct. On Clay soil m fields from Minnesota to New England and south 

 to the Gulf States. Occurs in eastern Pennsylvania and in Ohio. 



* Oreoweisia serrulata extends south as far as Tennessee and Kentuclcy, but is reported 

 thus far in Pennsylvania only from the eastern part of the State. Moist, shaded, cool 

 ledges. 



