370 RIKARD STERNER 



58 ff. (Kharkov); Taliev and Vojnovsky 1903, pp. 193, 194 (Samara); Sukascev 

 1903, pp. 327 fif. (Kursk); Korshinsky 1888 (East Russia)]. 



The continental marsh-plants that are found in South Sweden are remarkably 

 rare there, as a rule, and occupy a peculiar position owing to their mode of 

 occurrence. Many of them do not form part of a closed and stable marsh- 

 vegetation but of a sparse, more or less colony-like and temporary vegetation 

 on shores, or in localities more or less recently created by human intervention, 

 such as turf-cuttings, ditches, areas of new soil that have come into existence 

 through the lowering of the level of lakes and the like. 



Bidens radiatus and Scirpiis radicans are good examples of this. They have 

 been observed in a number of localities of the last-named kind in Central Sweden, 

 to which they might have spread quite recently and over great distances (see 

 Sernander 1901, p. 404; 191 1, pp. 278 ff.). Senecio palustris seems in Skane 

 to have some marsh occurrences, but as a rule it appears in about the same 

 fashion. — Cardamine parviflora, which has a number of sporadic occurrences 

 in Central Sweden, grows in sparse vegetation on sandy shores. — Carex vul- 

 pina would seem to grow, possibly with some exceptions, in places which have 

 been called into existence by the hand of man — ditches, ponds etc. (cf. Sa- 

 muelsson 1922 b). — In this way Arabis Gerardi occurs, rarely, on Gotland. 



Geranium pahistre and Cirsiiim oleraceum in general have natural marsh-like places 

 of growth (forest swamps). This is certainly the case with Scolochloa festucacea 

 (the shores of lakes and banks of rivers), Viola tiligijiosa (forest swamps and 

 shores), Euphorbia palustris (marshes and sea-shores), and Achroarithes monophyllos 

 (chalky marshes). To these may be added Sonchus palustris, which grew wild 

 in former days in a locality in the extreme west of Blekinge, probably in a reed 

 association (cf. Wahlstedt in »Botaniska Notiser» 191 1, pp. 17, 18). These spe- 

 cies, however, have a rather insignificant distribution, or a very small number of 

 occurrences, in South Sweden. Apart from a few localities, probably relics, near 

 Lake Malar, Alopecurus ventricosus grows in South Sweden only on sea-shores. 



The remaining species, Calla palustris, holds a peculiar position. It is abun- 

 dantly spread in the forest districts of South Sweden, and the places where it 

 grows are quite natural forest swamps. 



These species are very different from one another in the matter of distribution. 



Cirsium oleraceum. Euphorbia palustris and Geranium palustre are found in the 

 whole of Central Europe, Euphorbia even in large parts of Western Europe. 

 These species occur in the north-west of Germany: Euphorbia and Cirsium in 

 the west to about the Lower Weser, Geranium only as far west as Hano- 

 ver. They may be said to have a west-Scandinavian distribution branch running 

 out from there. Geranium and Cirsium are spread over parts of Denmark and Skane 

 and in southern Halland and have some occurrences further in the north in 



