A. W. Evans — N'orth American Species of Frullania. 29 

 Subgenus V.— DIASTOLOB A Spruce. 



ICey to the Species. 



Bracts and bracteoles (at least those of the innermost row) strikingly 

 dentate or spinose. 



Lobes of leaves marked by a line of discolored cells ; lobules of 

 bracts with a distinct segment or stylus on inner edge. 



17. I*. Sehoyniana, 



Lobes of leaves without discolored cells ; stylus of bracts not 

 distinct. 19. t. Donnellii. 



Bracts and bracteoles entire or nearly so. 



Lobules of leaves parallel with the stem. 18. Ji. Kunzei, 



Lobules of leaves widely spreading from the stem. 



20. I. CaroUniana. 



17. Frullania Selwyniana Pearson, List of Canadian Hepaticse, 1. 'pl. 1. 1890. 



Frullania Sullivantia Aust., Bull. Torrey Bot. Club, iii: 16. 1872 (not F. Sulli- 

 vantii Aust.). 



Frullania fragilifolia Ans,t.,\. c, Y\: 301. 1879 (not Tayl.). 

 Plate XIII. figs. 9-J7. 



Autoicous : plants appressed to matrix, reddish-brown or purplish : 

 stems irregularly pinnate : leaves imbricated, the lobe ovate, arching 

 over the stem and cordate at base, somewhat decurved at the rounded 

 apex, entire ; lobule close to the stem and subparallel with it, short- 

 clavate ; stylus minute, subulate ; underleaves distant, rhombic-oval, 

 bifid about one-third with obtuse lobes and sinus, entire or unidentate 

 on the sides ; leaf-cells of lobe thick-walled, trigones inconspicuous 

 except in the middle and toward the base, intermediate thickenings 

 scanty, discolored cells in a median line : ? inflorescence terminal on 

 the stem or a main branch ; bracts in about three pairs, unequally 

 bifid, the lobe ovate, acute (becoming obtuse as we recede from the 

 perianth), irregularly dentate, lobule narrower than the lobe, ovate, 

 acute, irregularly ciliate-dentate and bearing a distinct, usually 

 dentate segment or stylus below the middle of the inner edge ; 

 bracteole free, broadly ovate, bifid to below the middle, with acute 

 lobes and sinus, irregularly ciliate-dentate (becoming simply dentate 

 on receding from the perianth) ; perianth about a third exserted, 

 obcuneate, compressed on the sides, and with a strong postical keel, 

 abruptly narrowed into a short, broad beak, minutely setulose at the 



