OF WESTERN PENNSYLVANIA. S3 



small oval base gradually subulate-setaceous, nearly entire to 

 minutely denticulate ; costa wide, not well defined, practically 

 filling" the apex; basal leaf-cells rectangular to more or less 

 oblong-hexagonal, the upper cells often becoming linear and 

 forming a more or less distinct margin to the costa : seta short, 

 erect ; capsule oval or roundish, small but longer than the seta, 

 minutely obtusely apiculate, more or less castaneous or yel- 

 lowish when mature; calyptra cucullate, reaching about half- 

 way down the capsule, short rostrate, split almost to apex; 

 spores large, mature from April to June : antheridia naked in 

 axils of the perichsetial leaves. 



On moist clayey or sandy soil in old fields, along banks of 

 ditches, etc., in Europe, Asia and in North America, from New 

 England to Wisconsin and south to Alabama. 



Washington: Linn & Siinonfon. (Porter's Catalogue). 

 2. Pleuridium alternifonum [Dickson ; Kaulfuss] Rabenhorst. 



Densely cespitose, yellowish-green : stems about 5 mm. 

 high, simple, or longer with flagelliform innovations up to 2 

 cm. or more long ; stem-leaves lance-ovate to lanceolate, about 

 1 mm. long, the comal and perichsetial abruptly much longer ; 

 costa ending in the apex ; basal leaf-cells rhomboidal or rec- 

 tangular, above rectangular, small, moderately incrassate ; 

 perichastial leaves up to 3 or 4 mm. long, abruptly narrowed 

 from an oval base to a long linear-subulate acumen which con- 

 sists largely of the excurrent costa and is finely and closely 

 denticulate-muricate, the costa at base is broad and indistinct : 

 seta very short, erect; capsule oval, at apex obliquely conic- 

 apiculate, immersed, yellowish to brownish, cleistocarpous; 

 calyptra small, cucullate, split almost to apex ; spores large, 

 minutely roughened, mature in spring or early summer : auto- 

 icous, antheridial clusters gemmiform in axils of upper leaves. 



Sandy fields, roadsides, banks of ditches, etc., in Europe, 

 southwestern Asia, and in central and eastern United States. 

 Since this Manual went to press the species has been unexpect- 

 ly found as follows : 



Butler : In sandy meadow on south slope of hill 



two miles southwest of Glade Mills, April 

 20, 1913. O. E. J. and A. R. Hillard. 



Westmoreland : In sandy-clay meadow on gently sloping 

 hillside east of Blackburn, April 24, 1913. 

 O. ,E. J., G. K. J., and R. J. Sim. 



4. DITRJCHUM [Timm] Hampe. 



Dioicous or autoicous ; mostly low, cespitose. not radicu- 



I'jse, green to yellow-green, more or less shining: stem with a 



central strand, densely foliate, simple or little branched; leaves 



with a broad base, not sheathing, mostly long-canaliculate- 



