372 ^ ... RIKARD STERNER •■ 



where there is a maj:) showing its distribution). Viola, it is true, has but few 

 occurrences, but the general form of the distribution is much the same. 



Alopecurus ventricosus, as has been mentioned, occurs in South Sweden on 

 sea-shores. The distribution in tlie Scandinavian lands is peculiar and worth a 

 detailed account. The Scandinavian distribution of the species may be said to 

 consist of two parts, one northerly and one southerly. The former comprises 

 the coast of the Arctic Ocean (to the west as far as Senjen in Tromso Amt in 

 Norway) and inland behind this stretch of coast, mainly the Russian and Finnish 

 Lappmarks. To this part of the distribution-area also belong one or two occur- 

 rences at Haparanda and Tornea. The southerly area comprises the coasts of 

 the South Baltic: the south-western coast of Mnland from Satakunta (southern 

 Osterbotten: Vasa?) in the north to I'rcdrikshamn in the east, the coast of I'Lst- 

 land and Lettland (from Kandel on the (iulf of Finland to Libau in the south, 

 mainly on the islands; Kupffer 1906); the eastern coasts of South Sweden from 

 (Jregrund down to the east of Skane, and the coast of Ciermany, where however 

 it is known only from Hither Pomerania behind Rugcn and at Danzig. To these 

 must be added one or two occurrences in Denmark, one in the south of Zea- 

 land and one on Falster. Resides this the species has been observed on the 

 west coast of Sweden in Bohuslan (two localities), and at one locality in the 

 south-east of Norway near Larvik. 



What I would especially wish to call attention to in this place is the fairly 

 close accordance which is to be found between the southerly part of this distri- 

 bution-area and the distribution of Silene viscosa on the Baltic (see p. 325). It 

 would seem to be indisputable that the explanation of this lies in the fact that 

 the dispersal of the two species in the southern Baltic district goes on in a similar 

 manner. Neither species may have reached its full distribution in the region; and the 

 fact tliat they so nearly agree with one another points to vehicles of dispersal 

 which work in about the same limited field. 



We have thus found that the few marsh-plants of South Sweden that can be 

 regarded as continental ones largely consist of species with a peculiar mode of 

 occurrence, and that with some exceptions they are rare in the region and play 

 a very insignificant |)art in the vegetation. Several species, ov^^ing to their ca- 

 pacity for long-distance dispersal, have settled down, probably quite recently, on 

 localities brought into existence by the hand of man, where they appear as 

 colonists, often as ephemeral ones. Species which are jKUt of a more stabilized 

 vegetation, and which probably spread more step by step, have a very insigni- 

 ficant distribution in South Sweden. — We have also found tliat, with some 

 exceptions (Care.x vulpina and, possibly Viola uliginosa), these continental species 

 in their South Swedisii distribution do not reflect the formation of the region 

 in a continental-maritime respect. 



