22 CARL SKOTTSBERG, (Schwed. Südpolar-Exp. 



Especially instructive was a place on the south side of Pot Harbour, where a small 

 stream crosses the Poa-hinge, which over a large stretch has been changed into a 

 Polytriihum-hog (Fig. 4) where Pogonatitm alpinum occurs with enormous, firm 

 cushions, up to 3 or 4 m. in circumference and 3 — 5 dm high. P<?(?-tussocks in all 

 stages of destruction are seen here, more or less overgrown with Pogonatum. Some 

 of the cushions only show some tufts of the grass at their margin; I made sections 

 through two of them and found the remains of the killed grass in their centre. 

 I also cut through two pure Pogouatum-cushions, both containing a dense mass 

 of grass-peat. Between the cushions, in the wet depressions, grows the Rostkovia- 

 association. 



I am convinced that we once had a /W-community on this spot. The only 

 reason for its destruction that seems to suggest itself is that the stream, which winds 

 over level ground and is much branched, has been shifting its course a little for 

 the last ten or twenty years. That this space of time is quite sufficient for the 

 Polytrichaceae to attain a considerable size was clearly shown by a visit to Dr. 

 Wills old garden at the German station in Royal Bay, where 20 years before our 

 visit certainly no Polytrichum or Pogonatum at all existed; his plantbeds now were 

 overgrown with those mosses. 



2. The vegetation of the rocky shore. 



In all the coves and harbours mentioned in this paper, steep rocks come down 

 to the water in many places, mostly covered only with crustaceous lichens, but of- 

 fering some crevices and small shelves as a refuge to phanerogams and mosses. 

 Even here Poa flabellata grows, mostly in small tufts, together with the few plants 

 especially characteristic of such places. The most noticeable is Colobantlms subu- 

 latus, forming small, more or less globose cushions or filling up narrow crevices. 

 It is nearly as hard and compact as an Andine Azorella. In such places is also 

 found the small Hymenophyllum falklandicum, very densely matted. 



The moss vegetation will be illustrated with the following examples. 



May Cove: Bryum lamprocarpum Dicvanoioeisia grimmiacca. 



Orthotrichum crassifolium. 

 Jason Harbour: Orthotrichum crassifolium Willia grimmioides. 

 Moraine Fjord: Aneura cochleata Webera implexa v. nigrita n. var. 



Royal Bay: Dicranoweisia grimmiacea Orthotrichum crassifolium 

 » subinclinata Pottia austrogeorgica. 



