SCHISTOSTEGA OSMVNDACEA MOHR. 365" 



metallic lustre of many plants growing in deep shade is very 

 apparent in S. osmundacea, more especially in plants which are 

 vigorous in growth. Occasionally plants are met with that 

 approach in colour normal, or even slightly yellow, green ; but- 

 such plants are probably old or lacking in vigour, as strong, 

 healthy plants exhibit the glaucescent lustre in a very marked 

 manner. It is perhaps worth mention that one or two other 

 species of mosses are quite frequently found associated wdth 

 Schistostega, such as, for instance, Plagioihecium depressum 

 Dixon, Webera proUgera Bryhn, etc. ; and as these species grow 

 equally well in light of a far greater intensity, it points to the fact 

 of their having a considerable range of adaptation. Nor, so far 

 as I have been able to make out, does their association with 

 Schistostega in its feebly illuminated habitat entail any modifica- 

 tion of their structural details. 



Schistostega is a sufficiently striking plant to make its identi- 

 fication quite easy when its habitat is once comprehended, and 

 Dixon has aptly described it as resembling miniature fronds of 

 Lomaria sficant. Individually it is 8-12 mm. in height and forms 

 beds several inches square, usually on the sides of the burrows- 

 and crevices in which it dwells, more rarely on the floors. It has 

 been frequently described as growing in ivet sandstone caves. 

 I have never yet found any plants of Schistostega in a locality^ 

 that could with accuracy be described as wet ; on the contrary 

 it seems to avoid such spots. The Dartmoor localities, which 

 from its abundance and luxuriance may always be regarded as. 

 representing the ecological optimum of this plant, are by no 

 means wet ; in fact the absence of anything like coherence in the 

 soil upon which it is found growing makes it a very difficult plant 

 to collect satisfactorily, as it so readily becomes disintegrated 

 on detachment that the plants are lost amongst a handful of loose 

 earth. It would be more correct to describe its habitat as a damp 

 one. At the same time so good an authority as Mr. A. D» 

 Michael, F.L.S., has given a description (16) of a cave in Cornwall 

 he visited which was said to contain this moss. It is described 

 as a cave with dripping sides on the sea-shore, inundated by high 

 spring tides. The description of the greenish glow seen when 

 standing at the mouth of the cave is quite indicative of Schisto- 

 stega, but the statement that the same glow was apparent in the. 

 small pools on the floor of the cave scarcely suggests this moss. 



