86 



THE SCOTTISH BOTANICAL REVIEW 



mats of Cerastium trigymirn associate themselves with these 

 two plants. Later on Gnaphalium supimini steps on the 

 scene, or the long red creeping shoots of the five-leaved 

 Xdidy's rmntXe. {Alcheinilla pentaphyllea) become interlaced, so 

 as to form connected masses. " 



Brockmann-Jerosch (4) gives the results of examinations of 

 nineteen examples of snow-flushes, recording the number of 

 times each species was noted, Riibel (7) also gives results 

 from forty - eight stations. Both authors worked in the 

 Rha;tian Alps, an extensive area of high altitude. The 

 following table gives — for Scottish species only — the num- 

 ber of times of occurrence recorded from the above two 

 memoirs : — 



The species recorded for snow-flushes by Oettli (6) for the 

 Churfurst and Sentis areas are also included in the above 

 table. 



These lists are characteristic for stations on crystalline 

 rocks. The catalogue from calcareous rocks is much longer, 

 with few Scottish species, and has Salix retusa as a character- 

 istic plant. The Scottish lists, taken along with other 

 notes, suggest that the same association is represented as 

 on the crystalline rocks of Switzerland. It is probable that 

 in Scotland Cerastiuvi cerastioides and Veronica alpina also 

 occur on snow-flushes, while Poa alpina, Deschampsia 



