DICRANUM. 101 



o/Ls. suddenly narrowed above the wide base to long, fine, toothed points 9 



\Ls. gradually tapering 10 



/Leaves with basal wing serrulate 19. asperulum 



"\Basal wing entire, leaves falcato-secund 18. uncinatum 



/Ls. distinctly serrulate above, papillose at back of apex 11 



\Ls. entire, or serrulate at apex only, smooth or nearly so 12 



/Plant small, ls. strongly curled when dry ; capsule erect if. montanum 



\ Plant larger ; ls. scarcely curled ; capsule cernuous 12. fuscescens 



{Plant slender, densely matted with tomentum ; lower cells of leaves porose 

 14. elongatum 

 Plant less compact ; basal cells not porose (except molle and fuscescens ) 13 



/Plant small; leaves nearly all broken across ij. strictum 



•'XLeaves not fragile 14 



/Ls. strongly curled when dry, with distinct teeth at apex 16. flagellare 



4\Ls. not or slightly curled, entire or finely serrulate 15 



Upper cells of ls. all quadrate ; stem radiculose 16 



Upper cells (or some of them) elongate ; stem rooting at base only 17 



r /Basal cells rather short, not porose 13. Scottianum 



\ Basal cells longer, porose 12. fuscescens 



/Capsule suberect, furrowed, neck tapering ; seta short 1. fulvellum 



' \ Capsule cernuous, neck strumulose when ripe ; seta longer 18 



o/Tall ; ls. silky, basal cells porose ; capsule oblong j. molle 



\ Plant J-2 inches high ; basal cells not porose 19 



{Ls. flexuoso-patent ; male flower far below perichaetium 4. schisti 

 Ls. falcato-secund; male flower close below pericbastium 20 



/Ls. with few angular cells ; capsule short, obovate 2. falcatum 



\ Angular cells distinct, coloured; capsule oblong-cylindric .3. Starkei 



■»{ 



A. ARCTOA. 



1. Dicranum fulvellum Smith (Bryum fulvellum Dicks.) 

 (Tab. XVII. B.). 



Very densely tufted, dark or yellowish green, brown or 

 blackish below ; 1-2 inches high. Leaves secund, falcate above, 

 flexuose when dry ; from an oval base quickly narrowed to a 

 subulate limb, very narrow at apex and entire or minutely 

 denticulate; angular cells large, few, brownish, not inflated; the 

 basal narrow, linear, upper also linear but shorter, the marginal 

 row often of almost quadrate cells ; nerve very narrow at base, 

 forming the greater part of the subula. Capsule slightly exserted 

 on a short seta, reddish brown, oval, with an equal neck, or very 

 slightly asymmetric, wide -mouthed and almost turbinate after 

 the fall of the lid, sulcate ; lid obliquely rostellate ; peristome 

 teeth large, wide-spreading when dry. Male flower just below 

 the perichaetium, gemmiform. 



HAB. Clefts of rocks on high mountains. Not common. Fr. summer. 



