— 180 — 



few specimens together with Ditrichum pallidum and Pleuridium 

 palustre: Breidler»: Limpricht Laubm. DeutFchl. 



B. Leaves entire abruptly narrowed from ovate base. 

 G.D.subnIatnm Bruch. — Leptotrichnm Bruch; Ditrichum Lindb. 



Leaves otherwise as in D. pallidum. Capsule smaller, suboval 

 faintly sulcate; annnliis none; pedicel not long. — Clayey places 

 on rocks r. Eur. southern districts, France: Philibert. Italy: 

 Bottini; Arcangeli. 



2. Erythropodia. 



A. Tufts very tomentose, us. high and glossy. Leaves 

 gen. large; alar cells sometimes distinct subquadrate; costa long- 

 excurrent. 



7. D.flexicanlc Schleicher. — DidymodonSchl.; Ditrichum Hampe. 



Leaves long-subulate often denticulate, not appressed; cells 

 irregular gen. narrow: basal shorter often reddish; costa often 

 broad. Capsule brown. R. fruiting. — Rocks and stony ground, 

 -common. Eur. Sweden, Norway, Switzerl.i Austria, fruit.: Ven- 

 turi. Amer. Can.: Drumraond; Macoun. 

 * D.donsiim (Schimper a.« var.) Kindb. 



Leaves shorter and less patent; cells gen. short, upper suboval. 

 Tufts more dense and less glossy. — Eur. princ. in northern 

 districts. Sweden common, often fruiting!; M. Huss. Amer. 

 Can.: Macoun. 



B. Tufts not or sparingly radiculose, us. low and not glossy. 

 Leaves gen. not large; alar cells not distinct. 



a. Leaf-cells gen. narrow, rectangular. 



aa. Perichetial leaves sheathing. Peristome without basal 

 tube. 



S.D.TaginaiiS Sullivant. — Trichostnmum Sull. ic. m.; Ditri- 

 chum Hampe. 



Leaves from ovate base gradually short-subulate or acute, 

 entire or nearly so, appressed when dry, erect when moist; 

 cells narrow; costa percurrent or short-excurrent Tufts eradi- 

 culose not glossy, 1 or r. 2 c. m. high. — Earth and wet 

 rocks r. Eur. Norway: Geheeb, com. C. Mueller. Belgium: 

 Gravet. France: Lamy, com. Husnot. Amer. Can.: Macoun. 

 9.D.hnmoniallum Hedwig. — Didymodon Hedw.; Ditrichum 

 Hampe. 



Leaves (at least on fiidting stem) long subulate gen. entire, 

 us patent; cells gen. narrow; costa (at least on leaves of fruit, 

 stem) long-excuirent. Tufts us. low. Sterile shoots often 

 short-subulate with subpercurreut costa. — Sandy ground princ. 



