Pethybridge & Praeger — Vegetation South of Buhlin. 163 



is Scirpus ccespifosus, althougli, as a rule, mixed with a considerable 

 amount of stunted and apparently poorly-thriving Calluna. The soil 

 is thick peat, and, except in the hottest part of summer, when the 

 surface may be comparatively dry, it is thoroughly saturated with 

 water. Where the Scirpus grows in considerable tufts which are 

 only fairly close together (as, for example, on the flats above Glenas- 

 mole), and separated by a network of spaces of soppy peat, the 

 slipperiness thus produced makes walking over these bogs a very 

 tiring operation. In a few areas, however, where the Calluna and 

 other associates are very few and far between, the surface of the 

 ground is remarkably smooth, hard, and wet, and resembles that of a 

 lawn, with a vegetation of a uniform height of about six inches. 

 Under these circumstances the association, in what we may call its 

 pure form, contains remarkably few species, as the following list 

 shows : — 



Station 56. 



Scirpus csespitosus. Calluna vulgaris. 



]N"arthecium ossifragum. Erica Tetralix. 



Eriophorum angustifolium. Sphagnum spp. 



Of these, the first two are the only species which are at all 

 abundant, the rest being found scattered here and there ; the Calluna 

 in particular coming in only occasionally as odd tufts, or little islands 

 in the sea of Scirpus. 



A combination of the lists for the Scirpus association in its pure 

 form from five stations, gives the following : — • 



Scirpus c^spiTOSTJS. 5. Drosera rotundifolia, 2. 

 Calluna vulgaris. 5. Andromeda Polifolia. 2. 

 Eriophorum angustifolium. 5. Erica cinerea. 1. 

 Erica Tetralix. 5. Empetrum nigrum. 1. 

 Narthecium ossifragum. 5. Eriophorum vaginatum. 2. 

 Sphagnum sjt?^. 4. Eacomitrium lanuginosum. 1. 

 Cladonia rangiferina. 2. 



More commonly, however, the amount of Callima, E. Tetralix, 

 and EriopJiorum angustifolium is considerable; and the association 

 loses its lawn-like character, being, however, not unpleasant to 

 walk over, except for the wet. The composition of the associa- 



