igo TORTULACE^E. 



usually papillose and opaque ; capsule cleistocarpous, gymnos- 

 tomous, or with a peristome of 16 teeth entire or divided partially, 

 or cleft to base into 32 filiform papillose segments, straight or 

 twisted, on a very short basal membrane. 



40. BARBULA Hedw. 



Slender, tufted plants, usually -with a dull, fuscous tinge, 

 especially in the lower part. Leaves small, narrow, never wider 

 above and usually gradually narrowed to a slender point ; nerve 

 mostly vanishing in apex, rarely distinctly excurrent ; basal cells 

 small, rectangular, or similar to the upper, at apex usually very 

 small, often more or less iticrassate. Capsule small, resembling 

 that of the smaller forms of Tortula ; peristome from a very 

 short membrane, teeth 16, straight, short and imperfect, or long 

 and twisted, cleft or divided to base. Lid, calyptra, etc., as in 

 Tortula. 



A large genus, forming a fairly natural group, closely allied 

 to the last, but with a facies and growth distinct and easily 

 recognised with a little practice. B. unguiculata and B. convoluta 

 are the only British species the leaves of which, from their form, 

 might give rise to a doubt as to their position. 



B. Woodii Schp. from Killarney is, according to Braithwaite, 

 only Zygodon Mougeotii. 



("Nerve excurrent in a distinct mucro or cuspidate point ; (peristome long, twisted). .2 



(Nerve ending in or below apex 7 



/Leaf-margin strongly revolute from base to apex ; Is. about \ line' long 3 



(Margin plane or nearly so towards apex 4 



/Leaves obtuse, mncronate T2. revoluia 



3 (Leaves acute, cuspidate n. Hornschuchiana 



("Leaves tapering to acute points 5 



^ (Leaves more or less obtuse, mucronate or cuspidate 6 



/Nerve shortly excurrent ; cells rounded ; 9. gracilis 



-> (Nerve excurrent in a very long point ; cells more quadrate 10. icmadophila 



, /Leaves J line or less; perichretial Is. long, convolute 13. convoluta 



(Leaves usually over 1 line ; perichcetial Is. not conspicuous 14. unguiculata 



("Leaves long, strongly sinuose at margin, toothed at apex 8. sitaiosa 



' ( Leaves not sinuose, entire (except sometimes rubella) 8 



o/Leaves £ line or less ; perichjetial Is. long, convolute 13. convoluta 



(Leaves usually over h line ; perichjetial Is. not conspicuous 9 



/Leaves short, often obtuse (peristome short) 10 



" (Leaves tapering and acute, or long and sub-obtuse 11 



/ Ls. widely ovate-lanceolate ; nerve ending in the thick point ; green /. lurida 



(Ls. lanceolate, upper obtuse ; nerve ceasing below apex ; olive-brown... 3. tophacea 



/Lower ls. red; ls. often denticulate at apex ; paroicous or synoicous 2. rubella 



(Lower Is. not red ; ls. entire ; dioicous 12 



