367 



30 mm. (Ekstam. 1897). Several species of flies have been 

 noticed upon the flowers in Spitzbergen (Ekstam). In the 

 middle of June the plant appears to be in full flower every- 

 where and ripe fruit is found at the middle and end of August 

 (Andersson & Hesselman; Ekstam), but the flowering period may 

 continue as long as into September (Sept. 9; Norman I. c). 

 Fruit is set abundantly. 



The nuts are smooth and somewhat flattened, and the beaks 

 are rather long (Fig. 19); they are dispersed by the agency of 

 the wind (Ekstam 1897). 



According to Norman, in Arctic Norway this species is 

 not so particular in its requirements regarding habitat as R. 

 glacialis\ it occurs both at the shore and in the interior of 

 the country; in the lowlands and in the highlands (willow-zone). 

 In N.E. Greenland it is no doubt most frequent in the coastal 

 districts (Disen 1. c). In Arctic Norway it appears to grow by 

 preference in rather damp ground or in gravel, and is also 

 found in marshy localities. Hartz found it growing in a bog 

 in Scoresby Sound. 



The species is circumpolar but does not occur exclusively 

 in Arctic regions as it is also found in North America in the 

 Rocky Mountains, and in Asia it extends towards the south 

 as far as to the Baikal-Mountain regions and to Altai. In 

 Europe it occurs only in Finmark (Simmons 1. c). 



Anatomy. I am not prepared to say anything regarding 

 the main root; it probably dies early as is commonly the case 

 in the genus Ramincnlus\ the adult plant bears only adven- 

 titious roots. The anatomy of the latter does not differ in 

 any essential points from the root-structure described for R. 

 glacialis, which may very well be regarded as a type, at least 

 as far as the Arctic species of Ranunculus are concerned. 



The epidermis in the adventitious roots of the first 

 order has perhaps less tendency to collapse and the exodermis 

 is not so distinct as in R. glacialis; both the layers are 



24' 



