TORTULACE^:.] 



2O6 



'Tortula. 



genera under the old names, Tortula being used for the species with 

 broad green leaves, and more or less opake areolation, Barbula for those 

 with narrow leaves, becoming rust coloured or yellow, and the cells 

 incrassated or dot-like. We are thus able to bring under Barbula 

 mosses without peristomes to the fruit, but agreeing so closely in the 

 vegetative system with species of Barbula, that in a barren state it is 

 impossible to separate them e.g., Gymnostomum curvirostre . 



The teeth of the peristome in Tortula consist of two rows of cells, which 

 are not on the same plane ; the inner series larger paler and trans- 

 versely striate on a minute scale, the outer more solid and reddish. 



CLAVIS TO THE SPECIES. 



Teeth of peristome not united in a tube. 

 Nerve narrow, lamelliferous above. 



Capsule ovate, gymnostomous. pusilla. 



subcylindric, peristome imperfect. lamellata. 



Nerve very broad, covered above with short jointed filaments. 



Synoicous. brevirostris. 



Dioicous. 



Calyptra reaching half way down capsule. , stellata. 



only covering lid. 



Capsule erect, straight. ericcefolia. 



inclined, subincurved. aloides. 



Nerve free from appendages. 



Nerve much thicker toward apex. atrovirens. 



thin and regular. 



Leaves without a thickened border. 



Leaves with plane margins, points not hoary. 



Caps, oblong ; 1. broad, obovate mucronate. cnncifolia. 



cylindric, 1. subspathulate, long-pointed. Vahlii, 



Leaves with recurved margins and hoary hair-points. muralis. 

 Leaves with a thickened border. 



Plants short, simple, 1. acute, pointed marginata. 



tall, branched, 1. obtuse, mucronate. mucronata. 



Lower i f of peristome forming a tesselated tube. 



Nerve gemmiferous above. papillosa. 



Nerve smooth. 



Stem short, leaves yellowish green. 



Leaves piliferous, capsule oblong. canescens. 



Leaves cuspidate, caps, cylindraceous. 



Leaves broad, subspathulate, entire. snbulata. 



narrow, linear oblong, bluntly serrate. angustata, 



Stem elongated, 1. dingy green or rufescent. 



Leaves obtuse, emarginate. mntica. 



piliferous. 



Hair point smooth. hevipila. 



spinulose. 



Leaves squarroso-recurved. ruralis. 



erecto-patent 



Dioicous, olivaceous green. montana. 



Synoicous, ferruginous. princeps. 



Sect. i. DESMATODON (End.). Stems short ; leaves like those of 

 Pottia, often hair-pointed. Peristome a short basal tubular membrane, bearing 

 32 teeth, filiform, free or united at base by transverse bands, slightly 

 twisted or spirally contorted. 



A. Pterygoneuron. Nerve on the upper surface bearing 2 or 4 vertical 

 lamellae. 



