THE CONTINENTAL FLORA OF SOUTH SWEDEN 283 



ing up of the ground by the freezing of the water. The species can, however, 

 though rather seldom, form part of a halophytic vegetation on the shore. At 

 Sodvik in the parish of Persnas on Oland I have observed Artemisia rupestris 

 on the sea-shore, growing together with Artemisia maritima, Juncus Gerardi, and 

 Suaeda maritima (comp. K. Johansson 1897, ]). 115). 



Pla?itago temiiflora (Plate 13) has only one definitely known occurrence outside 

 the South Russian and Hungarian steppes, namely Oland. It is distributed all 

 over that island on the Alvar-pavement. In spring, when the species has its 

 vegetative season, its stations are damp. The soil is a very thin crust (only a 

 few cm. thick) of mouldy, strongly calcareous -^alvarino-A on the limestone pave- 

 ment. The ground is already dried up by Midsummer. The composition of 

 the vegetation may be illustrated by the analyses in Table 7, Appendix II. 



Artemisia laciniata Willd. Korshinsky (1. c. p. 219) says about the mode of 

 occurrence of this species in Siberia: »Non solum in salsis, sed etiam in rupibus 

 et in pratis silvaticis vel inundatis occurrit.» Besides those on Oland, this species 

 has only three occurrences in Europe. In Lower Austria it is found at Lassee and 

 there it occurs, according to Beck (1890), »auf feuchtem, salzhaltigem, lettigem 

 und sandigem Boden» (p. 32). In Germany the species occurs, together with 

 A. rupestris, in tw^o saltish places in Saxony and Thuringia. On Oland it be- 

 longs to dry meadows (see the analyses in Table i. Appendix II), a mode ot 

 occurrence which corresponds to »in rupibus et in pratis silvaticis». 



The way in which Artemisia rupestris and Plantago tenuiflora occur outside 

 the steppes is worthy of special notice. The species show themselves to be in- 

 dependent of any large amount of salt in the soil. The characteristic feature of 

 their occurrence on Oland and Gotland is the extreme development of the habitat 

 in another respect. The ground is strongly calcareous and nearly dried up during 

 a considerable part of the vegetative season. No doubt these two species have, 

 like certain other species in the peculiar Alvar-flora, a high osmothic pressure 

 (Falck 1913). Thanks to this inter alia they are able to stand such extreme habitats. 



Species of the Stipa Steppe, the Sand Steppe, and the Meadoiu Steppe. The 

 steppe species which form part of the South Swedish flora have in many cases 

 a large distribution in the forest region of Central and Northern Russia. They 

 appear here partly on cliffs, partly in a xerophilous herb and grass vegetation 

 which attaches itself either to the meadow steppe or otherwise more or less to 

 the sandsteppe. 



The meadow-steppe-like vegetation is found on southerly exposed slopes, 

 especially such ones with calcareous soil (Korshinsky : »declivia aprica argillosa vel 

 calcarea*) in the whole of the forest region. The sand-steppe-like vegetation 

 seems to occur especially in tracts with a scanty rainfall in Middle Russia, chiefly 

 as ground vegetation in thin pine forests. 



