216 BULLETIN OF THE UNIVERSITY OF WISCONSIN. 



Leaves decurrent. 

 With a broad border. 



Leaves short-pointed B. bimum, 1 229. 



Leaves long-cuspidate .... B. cuspidatum, 297. 

 Without a border B. lonchocaulon, 229. 



B. Polygamous. (C) 

 Leaves long cuspidate by excurrent costa, not bordered B. proyinciale, 230. 



C. Autoicous. (D) 



Leaves bordered, costa percurrent or excurrent. 



Border wide, 5-6 rows of cells, distinctly revolute B. pallescens, 8 231. 



Border narrow, faintly revolute . . B. ancectangiaceum, S28. 



Leaves not bordered. 



Costa excurrent B. sulbrotundum, 231. 



Costa vanishing below the apex B. teres, 306. 



D. Dioicous. 



i. Costa not excurrent, or when excurrent forming a short point only 



(2 on p. 218.) 



a. Leaves obtuse. 



Distant, broadly ovate or oblong, rounded . B. cyclophyllum, 237. 

 Thickly clothing stem, generally imbricate, narrower. 

 Not bordered. 

 Leaves strongly decurrent ... B. obtusifolium, 825. 



Leaves not decurrent B. capitellatum, 813. 



Bordered, sometimes indistinctly. 

 Dull olive-green, margins strongly revolute. 



Membrane of endostome ^ length of peristome B. Muhlenbeckii, 233. 

 Membrane of endostome low . . B. ruMcundulum, 814* 

 Yellowish or dull green or purplish. 

 Costa vanishing below apex, tips of branches crimsoned. 

 Cells polygonal, thick walled B. miniatum, 233. 



Cells rhombic, sub-quadrate below . B. Atwateria), 234. 



Costa percurrent, red, branch tips green B. percurrentinerve, 312. 



1 See Appendix, nos. 298, 299. 

 a See Appendix, nos. 303, 304. 



