Alpine and Arctic Floras 



has been done both in the Berlin and in the Zurich 

 botanical gardens, it changes into Juniperus communis. 

 This has been tried both with seeds and by transplanting 

 a mature specimen. 5 



The distribution of Juniperus nana is very interesting. 

 It occurs in the Scotch highlands, Wales, and West- 

 morland, to 2700 feet altitude. It is also found in the 

 Alps and Caucasus, to 3575 metres (1 1,600 feet) altitude 

 in the Himalayas, and it is also widely scattered over 

 the arctic regions both of America, Europe, and Asia. 



Its growth is extraordinarily slow. An ancient plant 

 103 years old was only 48 mm. in diameter (1.1811 

 inch) and increased in thickness by only .9 mm. per 

 annum (.035633 inch per annum). 



This dwarf, stunted habit of many alpine and arctic 

 plants may be quite simply explained by the fact that 

 they have a very short season to grow in, and therefore 

 have neither time nor (at least in Tibet and Siberia) 

 water enough to become of a respectable size. 



Some of our far too hardy and adaptable weeds seem 

 to thrive both at great altitudes in the Caucasus or 

 Tibet, and in the arctic regions, as the following short 

 list clearly proves : — 



Ranunculus acris (buttercup) 

 Taraxacum officinale (dandelion) . 

 Festuca ovina (sheep's fescue) 

 Capsella bursapastoris (shepherd's 



purse) 



Euphrasia officinalis (eyebright) . 

 Poa annua 



But in Switzerland, or even in our own mountains, 



* Sewell. 6 t White. 



95 



