KEY TO THE GENERA AND SPECIES OF BRITISH HEPATIC^; 166 



{Rootlets white, leaves frequently reddish, usu. with a distinct mar- 

 ginal row oflarger cells, at least in the fertile stems crenulata 

 Rootlets purple, or some at least hyaline red 2 



of Paroicous ; bracts \ attached to per obovata 



■ [ Usu. dioicous ; one bract usu. free, the other -^ attached to iper.... hyalina 



NARDIA. 



[Paroicous; leaves of fertile stems usu. emarjSfinate ; per. almost at 

 ij right angles to stem geoscyphus 



(Dioicous; leaves entire, rarely emarginate ; per. not as above 2 



[Stems without rootlets, or nearly so ; plant soft, brownish, aquatic ... 

 2 \ comjpressa 



(stems with many rootlets; plant firm, leaves glistening scalaris 



MARSUPblLLA. 



- j Leaves distant, scale-like nevicensis 



(Leaves approximate or imbricate 2 



2 (Paroicous or synoicous 3 



\ Dioicous 5 



of Sinus and lobes obtuse, rarely abruptly subacute olivacea 



(Sinus and lobes acute 4 



. j Leaves broadly ovate to subrotund ustulata 



1 2-3 times larger, leaves laxer, cordate at base siJarsifolia 



[Leaves appressed when moist, rather pellucid, deeply and acutely 



5-^ lobed ; plant small, resembling copper wire Stableri 



(Leaves patent or erecto-patent when moist, opaque; plant larger... 6 

 [Lobes and shallow sinus usu. obtuse; margin usu. reflexed 



6 i eynarginata 



( Sinus acute, deeper, to \ divided; margin not reflexed 7 



[ Lobes acu; e ; plant small Funchii 



7 j Lobes rounded ; leaves obovate from a narrow sheathing base, plant 

 ( larger sphacelata 



AC OLE A. 



- (Leaves patent from an erect sheathing base alpina 



"(Leaves appressed; plant smaller 2 



[Leaves refuse, margins much lacerated, apex of stem frequently 



2 i recurved cor a llioides 



(Leaves more deeply divided, margins not or little lacerated 3 



of Margins distinctly crenulate 4 



(Margins not or hardly crenulate 5 



Plant silvery white, more rarely greenish, stems clavate ohtusa 



Plant brown or olive, smaller, stems of nearly the same diameter 

 throughout ; marginal cells elongate crenulata 



_j Paroicous; leaves oval or oblong, incised only |-| adusta 



I Monoicous or dioicous ; incision deeper 6 



n ( Monoicous ; reddish brown, rootlets few, short; sinus acute... co/t/er^a 

 (Dioicous 7 



[Larger, brownish yellow to greenish; leaves very conspicuous, margin 



_J reflexed in the upper leaves, sinus acute concinnata 



1 Smaller, olive-brown or nearly black; leaves thick, margins plane, 

 \ sinus rather obtuse, and forming nearly a right augle...cras5i/o/ia 



