CLIMA TIC FA CTORS 



123 



2. Vegetative increase by creeping shoots as in Luztda spadicea, Salix herbaccu, 

 Arenaria hiflora, Cerastium cerastioides, Alchemilla pentaphyllea, Veronica alpina. 



3. Dense sod or tussock-forming growth, with capacity for spreading periph- 

 erally. No annuals. 



4. Utmost reduction of the individuals. The snow-pocket plants are the 

 pygmies of the alpme flora. Accessory leafy shoots are suppressed and the repro- 

 ductive activity extended to the Umit. On a tiny stalk is perched the terminal 

 inflorescence. Cardamine alpina, Ranunculus pygmaeus, Soldanella pusilla, S. 

 minima, and Gnaphalium supinum are each among the smallest members of their 

 respective genera. 



5. Extremely rapid development after the snow melts, and early ripening of 

 seed. Witliin a few weeks the life cycle is completed from bud to fruit. 



Fig. 69.— Snow pockets with Salix herbacea in the Tatra (1,960 m.) showing Salix 

 herbacea, Ligusticum mutellina, Soldanella carpatica. {JPhoto by Zlatnik.) 



The Salicion herbaceae (Fig. 69) is marked by a series of pronounced 

 characteristic species, whose optimum of Hfe conditions falls within the 

 realm of the community, i.e., Cardamine alpina, Arenaria hiflora, 

 Alchemilla pentaphyllea, Soldanella pusilla, ancient endemics of the 

 central European alpine system. 



Even in the forest areas of the subarctic zone and of the subalpine 

 levels of the Alps and lower mountains, the effect of snow upon the 

 forms of plants is everywhere demonstrable. Heavy snow masses 

 which are not too late in melting favor the development of stands of 



