u{ 



KEY TO THE GENERA AND SPECIES OF BRITISH HEPATIC^ 161 



„ (Acrocarpous, flagellae few heferostipa 



i Cladocarpous, flagelhe immerous .flaitans 



Q ( Leaves with an injflexed auricle curvifolia 



(Leaves without an inflexed auricle 9 



q (Leaves spinous-tootlied, complicate dentata 



(Leaves not spinous-toothed 10 



j-^jStips. present on stem 11 



(No stips. on stem 15 



^ , j Paroicous ; involucre swollen Jackii 



{ Monoicous or dioicous , 12 



.n (Monoicous elachista 



1 Dioicous 13 



-jQ I Cladocarpous ; lobes of leaf ending in a claw-like apiculus ceraria 



( Acrocarpous 14 



Per. 3-angled ; lobes of leaf acute, cells lax, pellucid ...Lammersiaiia 

 Per. usu. 4-6-angled ; lobes of leaf subacute, cells o-pd^q}ie...divaricata 



,~ ( Monoicous; per. longly ciliate, cilia about 5 cells long comiivens 



(Dioicous 16 



, ^ f Bracts ent ' re 17 



(Bracts toothed 19 



) Bracts | divided into lanceolate segments ; leaves decurrent, with long 

 m. or 1. conniveut segments hibernica 

 Bracts ^-^ divided, segments not lanceolate ; mouth of per. with setae 

 1-2 cells long 18 



.r,\ Per. with a single layer of cells .jjallida 



(Per. with two layers of cells in the middle lunidcBfolia 



jqjPer. usu. 4-6-augled, acrocarpous divaricata 



(Per. 3-angled, cladocarpous 20 



{Leaves subimbricate, incurved when dry, usu. fulvous ; mature per. 

 3-keeled throughout, mouth setose or ciliolate cateniilata 

 Leaves usu. distant, whitish ; mature per. 3-gonous at the upper part 

 only, mouth minutely setulose leiicantha 



PLEUROCLADA. 



[Leaves very concave, patulous; stips. frequently with a tooth 



j albescens 



(Leaves less concave, patent or erecto-patent ; stips. QniiVQ...islandica 



SCAPANIA. 



(Mature leaves from middle or lower part of stem must be examined.) 



j^ (Leaves verrucose 2 



( Leaves not verrucose 3 



(Ant. lobe triangular-ovate to subrotund, incumbent ; plant usu. more 

 slender, with post, lobe ciliate-dentate asperci 

 Ant. lobe ovate-subquadrate, erecto-patent or reflexed, apex acute, 

 j usu. much more divergent from the stem ; jjost. lobe dentate or 

 V almost entire cequiloha 



„ J Lobes equal or nearly so 4 



(Lobes unequal 6 



(Prostrate, strongly creeping; ant. lobe rather smaller, almost oblong, 



4 \ outer angle divergent, rather acute BartUngii 



(Ascending or erect ; lobes rotundate 5 



