ON THE PLANT REMAINS IN THE SCOTTISH PEAT MOSSES. 



55 



into peat-hags ; indeed, so extensive and deep are the channels that on a clear day they 

 can be well seen from a distance of 12 miles. A nearer view shows that the outline 

 of the hills is ragged or like the edge of a saw, due to the depth of the numberless 

 peat-hags. 



The vegetation, despite the low elevation of these hills, is unlike that covering the 

 ground at 100 or 200 feet in the San dness- Walls district. Rhacomitrium lanuginosum 

 is the dominant plant in places, and many of the hillsides are covered with Rhacomitrium 

 moor with stunted plants of Calluna vulgaris, Erica Tetralix, Scirpus csespitosus, 

 and Empetrum nigrum. 



Betula nana 

 Calluna 



Betula alba 



Structureless 

 peat and clay 



Salix Arbuscula 



Sand 





CM <.,. 



*^M^> 



feKSS 



Level of Loch 



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Fig. 3. — Section on the banks of Sma Loch, Shetland. 



The general sequence over these hills is as follows : — 



Characteristic Plants. 



1. Scirpus cxspitosus. 



2. Calluna vulgaris. 



3. Salix sp., Arctostaphylos alpina. 



4. Calluna vulgaris. 



5. Betula alba. 



6. Empetrum nigrum. 



7. Salix reticulata. 



8. Potentilla Comarum. 



9. Carex sps. 



Accompanying Plants. 



1. Rhacomitrium lanuginosum. 



Kriophorum vaginatum. 

 2. 



3. Empetrum nigrum (abundant). 



4. Eriophorum vaginatum, Sphagnum. 



5. Corylus Avellana. 



6. Carices. 

 7. 



8. Salix Arbuscula (1) 



9. Hippuris vulgaris. 

 Sand and clay. 



Comparing this sequence with that in the Sandness-Walls area it will be seen that 

 whilst some of the strata contain a slightly different flora the general facies of the plant 



