u— f 
114. Pterygoneuron Juratzka. a 
A. Capsule immersed; calyptra mitriform, Leaves with long — 
rough | hairpoint. 
1.P.subsessile Bridel. — Gymnostomum Brid.; Pterygoneuron 
Jur; Pharomitrium Schimper. 
Leaves suboval or obovate subacute not reflexed, papillose at f 
back. Capsule oval-globose; pedicel shorter; lid rostrate; peri- 
stome none. Stem 2—5 m. m. high. — Sand and clay r. - 3 
Eur. Austria: Berggren. Germany: Schultze. Amer. Can.: Ma- 
coun. 
B.  Pedicel exserted; calyptra cucullate. Leaves with smooth 
point. eee 
2.P.eavifolium Ehrhart- — Pottia Ehrh.; Pterygoneuron Jur. 
Differs also from the last in leaves smooth at back, — Clay 
soil, often on walls. Eur. not uncommon. Sweden! France: 
Husnot. Amer. Can.: Macoun; Drummond. 
3.P.lamellatum Lindberg. — Tortula Lindb.; Pterygoneuron 
Jur; Barbula cavifolia Schimper. 
Differs from the last: Leaves papillose at back, faintly reflexed 
below; costa shorter excurrent. Capsule oblong-cylindric; perl- 13 
stome slightly twisted, loosed with difficulty; basal membrane m 
clathrate. Stem somewhat higher. — Wet clay soil r. Eur e 
France: Bescherelle, - Austria: Berggren. | 
115. Didymodon Hedwig, in part. ; 
A. Leaves gen. entire; cells small at least the upper, r. (in 
Stegonia) large. ge 
à. Leaves not reflexed, often involute. Peristome not twisted. 
I. Stegonia. Leaves. close also when moist, smooth entire 
very broad concave or involute; cells large.  Perichetial leaves. 
not sheathing. Stem short. Monoecious. Spores large. — 
IL Trichostomum. Leaves not imbricate when moist, us. 
erisped when dry, papillose us, narrow. Spores small. 
l. Pusilli. Peristome slightly twisted. Plants small; stem 
very short. Monoecious, 
m Crispuliformes. Peristome not twisted. Dioecious. Plants 
ger. i 
b. Leaves not involute gen. reflexed. 
aa. Leaves half-sheathing, sometimes dentate above. 
MI. Erythrophyllum. oe 
Leaves reflexed papillose us. pointed 
by a long pellucid apical cell; basal cells bong. hyaline or finally 
reddish. . Perichetial leayeg sheathi : le straight. 
Tufts us. rusty red. Us, eee Peristome pa i 
