Jennings: Manual of Mosses — 2 Dicranaceae 49 



Key to the Species 



A. Calyptra mitrate; capsule with stomata immersed in middle of wall 



(Sporledera palustrti (Br. &. Sch.) Hampe =^ P. palustre (Br. & Sch.) Bryol. Eur.) 



A. Capsule split almost to apex B 



b. Narrow upper part of leaf shorter than the broadened basal part C 



B. Narrow part of leaf much longer than broad basal part D 



C. Leaves gradually narrowed from lance-ovate base to serrulate apex 



(P. Ravenellii Austin) 



C. Leaves abruptly mucronate and smooth above from broad serrulate base 



(P. Sulltvantii Austin) 



D. Basal cells of leaf about 2-5:1 \. P. subiilatum 



D. Basal cells of leaf about 5-8:1 (P. acuminatum Lindberg) 



1. Pleuridium subulatum (Hedwig) Lindberg 



(P. allernifoHum [Dickson; Kaulfuss] Rabenhorst; 

 Phascum subulatum Schreber) 



Plate LX 



Densely gregarious to cespitose, yellowish-green: stems usually simple, 

 about 2-6 mm high; lower stem-leaves lance-subulate, short; comal and peri- 

 chstial leaves m.uch longer, more or less erect or ascending, from a small oval 

 base gradually subulate-setaceous, canaliculate, nearly entirely to minutely 

 denticulate; costa wide, not very well defined, prartically 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 distina margin to the costa: seta 

 shore, erect, about as long as the capsule; capsule oval or roundish, about 1 mm 

 long, obtusely apiculate, more or less castaneous or yellowish when mature; 

 calyptra cucullate, reaching about halfway down the capsule, short rostrate, 

 split almost to apex; spores large, mature from April to June, minutely rough- 

 ened; antheridia naked in axils of the upper or median 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. 



Butler Co.: In sandy meadow on south slope of hill two miles southwest of Glade 

 Mills. April 20. 1913. O.E.J, and A. R. Hillard. Washington Co.: On stony ground, 

 near Washington, Linn and Simonton, May 2, 1892, and May 6, 1893. Westmore- 

 land Co.: In sandy-clay meadow on gently sloping hillside east of Blackburn, April 24, 

 1913. O.E.J., G.K.J.. and R. J. Sim (figured). 



4. DiTRlCHUM [Timm] Hampe 



Dioicous or autoicous; mostly low, cespitose, not radiculose, 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-canalicu- 

 late-subulate, imbricated to erect- spreading or secund, when dry mostly a little 

 curved or straight; costa broad and flat, percurrent or excurrent, usually filling 

 the upper part of the acumen; leaf-cells rectangular, more or less prolonged, 

 alar cells not inflated: seta elongate, erect; capsule erect or a little cernuous, 

 symmetric or unsymmetric, sometimes weakly arcuate, mostly ovate to oblong- 



