PLAGIOBRYUM. 313 



lines long; mouth small, oblique, pointing downwards; lid 

 conical apiculate ; outer peristome teeth a little shorter than the 

 processes of the inner, cilia rudimentary. Dioicous. 



Hab. Clefts of moist mountain rocks. Not common. Fruiting in autumn. 



Like many dioicous species this pretty moss is much more commonly found 

 barren than fertile ; in this state it bears a close resemblance to Bryum argenteum, 

 but that species never exhibits the vinous red colour which is usually markedly present 

 in this plant ; the cells too are hardly half the size with firmer walls, the nerve 

 vanishes or at least becomes very indistinct soon after reaching half way-up the leaf, 

 while in our species it is distinct at least to the base of the acumen, and is frequently 

 continuous. From the next species it differs in the longer-necked capsule less curved 

 and swollen, the plane-margined wider leaves, and shorter nerve, and the proportion- 

 ately longer teeth of the outer peristome. The long, asymmetrical, horizontal fruit is 

 very curious in appearance, and is somewhat variable in length, form and direction. 

 It is only when gathered at just the proper period of maturity that the neck of the 

 capsule can be properly seen ; in young capsules, as in old and empty ones, the 

 distinction between capsule and neck becomes indistinct. 



The beginner must beware of confusing the present plant with Bryum filiforine 

 (Bryum julaceum Sm. ) ; the likelihood of so doing, however, arises more from the 

 similarity of their synonymy than from any very close resemblance in the plants them- 

 selves ; Bryitm filiforme being a more slender, rigid plant, without the red tinge of 

 the present species, with much narrower cells and quite different fruit. 



2. Plagiobryum demissum Lindb. {Meesia demissa Hornsch. ; 

 Zieria demissa Schp., Syn.) (Tab. XLII. K.). 



Resembling the last species ; shorter, rarely more than % 

 inch high, reddish ; leaves less imbricated and concave, render- 

 ing the branches less julaceous; oblong-lanceolate, acuminate, 

 margin usually recurved, nerve (in the upper leaves at least) 

 excurrent, cells longer and narrower, especially towards base. 

 Seta strongly arcuate or cygneous, almost geniculate, at summit ; 

 capsule shorter, more gibbous and swollen, the neck shorter, 

 equalling the capsule in length, the whole usually more curved, 

 when dry sub-erect, iyi.-2 lines long ; mouth very oblique; outer 

 peristome teeth only about half the length of the processes, cilia 

 present, rudimentary. 



Hab. On the ground and among rocks in exposed spots on high mountains, 

 very rare ; Ben Lawers and Craig Chailleach, Perthshire. Fr. autumn. 



Differs from the first species in the shorter stems, less julaceous branches, more 

 excurrent nerve, and other points. It is a plant likely to be passed over, in the barren 

 state, as a small Bryum ; but the fruit is quite distinct ; smaller than in P. Zierii, and 

 more curved and irregular, but otherwise much resembling it. 



77. BRYUM Dill. 



Stems producing innovations, usually in pairs, below the 

 flowers, thus becoming repeatedly dichotomous and rendering the 



