294 RIKARD STERNER 



and Senecio vernalis, which are weeds or colonists; Salvia pratensis and Lavatera 

 thuringiaca which are probably fugitives from cultivation (cf. Sernander igo8, pp. 



224 ff.). 



Regarding their mode of occurring in South Sweden certain steppe species 

 hold a position the distinct characterisation of which is difficult. The species 

 chiefly occur as anthropochores but, besides, they also may have localities similar 

 to those of real natives. Some of these species will here briefly be mentioned. 



Draba nemorosa is distributed over the whole of East Europe, as a real native in 

 the steppes, dry hillsides etc. and as an anthropochore. Its distribution in Swe- 

 den is treated by Sernander (1908, p. 223) and Erodin (1917, p. 334), who has 

 made a distribution map. In the east of Central Sweden the species has a number 

 of localities, a few of which are herbaceous hillsides (as in the neighbourhood of 

 Upsala), the main part, however, more decidedly artificial habitats of different 

 kinds, where the species appears as a colonist. 



Melampyrum arvense. As a weed-plant it is distributed over the whole of Central 

 Europe, being observed as a casual even in South-Eastern England. In South 

 Sweden it is distributed over the coast-districts, especially in the South-East Swedish 

 flat regions. It is often observed in herbaceous hillsides but is also often met 

 with as a weed-plant. According to the statements in taxonomic works this mode 

 of occurring might have been its principal one in former days. This is also 

 indicated by its Swedish name ■>->Pukvetc-i>, [cL Sernander 1. c, p. 226). 



Malva alcea is widely distributed in South-Eastern and Central Europe as a 

 real native occurring chiefly in the »Trift formation ». As a certainly introduced 

 plant it also occurs in Western Europe. In South Sweden it is widely distributed, 

 in most cases doubtless as a fugitive from cultivation. In South-Eastern Sweden, 

 especially on Oland and Gotland it is rather common in dr}- meadows, on road- 

 sides, balks, and hillsides, and, perhaps, it might be a native in this region. 



Lepidium laiifoliuin is widely distributed in the steppe-districts in Central and 

 Western Asia and in South Russia, especially in salt-stcppes (cf. N. Busch in 

 Flora Sibirica, 19 13). In South Sweden it occurs on the Baltic coast partly at 

 the ports as an introduced plant (probably by ballast); partly on the sea-shore 

 far from ports, where it appears as a real native. Perhaps, we have here about 

 the same state of things as in the case of Silene viscosa and Isatis tinctoria (see 

 later on p(). 324 IT.). 



The occurrence and distribution in South Sweden of the above mentioned 

 species are, of course, of some importance in the judging of the continental 

 character of the South Swedish vegetation. They give us an evidence of clima- 

 tic conditions favourable to xerotherniic plants, existing in the district. 



