DICRANACEAE 23 



We have only two genera of this subfamily, Bruchia and 

 Pleuridium. Bruchia has capsules with a conspicuously de- 

 veloped neck, so that the capsules are pear-shaped. Because of 

 this long neck the genus is often put in the Trematodonteae, 

 but it seems most convenient to follow Limpricht in this matter 

 and certainly no violence is done to natural relationships. 



BRUCHIA Schwaegr. 



With the characters of the subfamily. Distinguished from 

 Pleuridium (except P. palustre) by the pear-shaped capsules and 

 mitrate calyptra; often growing with it, but distinguished 

 easily by a hand-lens by the characters given. Our species 

 catch the eye when growing with Pleuridium by reason of the 

 partially exserted capsules. 



Paroicous; capsule ovoid; stems up to 1 cm. long; leaves nearly smooth. 



flexuosa 

 Autoicouj; capsule pyrif 3rm; st;ms up to 3 mm. long; leaves subpapillos?. 



Sullivantii 



B. Sullivantii Aust. Lawrence and Woodhaven, L. Id.!!; 

 West Farms, Sanial, Bx! May. Probably frequent in rather 

 dry fields, often occurring with Pleuridium subulatum which 

 matures its spores at least two weeks earlier. 



B. flexuosa (Sw.) C. Muell. Mrs. Britton's garden and old 

 fields, New Dorp, S. Id., E. G. B., Bx!; "Wet meadows about 

 Closter and Camden, N. J.," Muse. App. 56. 



PLEURIDIUM 



Plants annual or perennial, in dense cushions; stems very 

 short, simple or branching; upper leaves longer than the lower; 

 more crowded, erect-spreading (except in P. Sullivantii) or 

 secund, not crisped; costa excurrent or percurrent and forming 

 most of the apex; capsules ovoid-globose, apiculate; calyptra 

 cucullate (except in P. palustre). Growing in light sandy soil, 

 often among grass. Spores in spring. 



Besides Bruchia the other genera most likely to be confused 

 with Pleuridium are: Archiaium, differentiated by having only 

 about sixteen very large (25 mm.) smooth spores and capsule 



