322 R IK ARD STERNER 



land, to the arable area in southern Dalsland and to occurrences of shell banks 

 on the coast of Bohuslan. 



Disregarding Inula ensifolia and Stipa pennata, which in Vastergotland have 

 only very inconsiderable and isolated occurrences — the most north-westerly ones of 

 their European distribution — the following species reach in this region the 

 north-westerly limits of their European distribution: Asperula tinctoria (Plate 5), 

 Phleum Boehmeri (Plate 5), Polygala comosa (p. 316), Prunella grandiflora (Plate 6), 

 Seseli libanotis (p. 334), and Trifolium montanum (p. 301). Except Polygala 

 and Prunella, these species, however, have one or a tew isolated occurrences 

 farther in the west in the neighbourhood of Christiania. 



The great contrasts in the nature of the soil in Vastergotland appear in very 

 sharp distribution boundaries. It might be questioned whether such sharp difTer- 

 ences in the character of the vegetation and the flora as occur in this district 

 can be found anywhere else in South Sweden. The species in question are 

 confined to the calcareous districts. Immediately to the west of Falbygden the 

 barren plain called »Svaltorna» pushes in a wedge of land towards the north, 

 to a great extent occupied by pine-planted heaths on sand and large moor-land, 

 and beyond a large arable plain comes in, whose moraine and clay are, at least 

 in the upper layers poor in lime. 



Even the species that do not reach their westerly limits in South Sweden but 

 show their continental character by an incomparably richer distribution in tlie 

 eastern parts, have the westerly limit of this richer part of the distribution area 

 in the calcareous districts. The species are richly distributed in Falbyden and 

 the neighbourhood of Kinnekulle but are missing or very scarce further west, for 

 instance Viola rupestris (p. 3 1 9), Crepis praemorsa (p. 3 1 5), V^eronica spicata (p. 310). 



The fact that a very great number of species show an irregular distribution 

 in Smaland has long been subject to the attention of scientists (E. Fries »i825»; 

 Wahlenberg 1833, pp. XL ff.; Scheutz 1857 ^"^ 1861 , Hard af Segerstad 1912). 

 The most prominent features of the flora of Smaland are that southerly, » nutri- 

 tion-exacting*, xerothermous species are confined to, or have their chief distri- 

 bution in the eastern part of the province, while westerly or northerly, less ex- 

 acting species are preferably or only found in the south-western part. Scheutz 

 has pointed out that a great number of species do not reach far inside the Baltic 

 coast, and that a likewise considerable number of species reach their western 

 Hmits in the central part of the province (the country about Vaxio). A closer 

 study of the distribution of the species in Smaland and their causes offers much 

 of interest. As a similar investigation is being carried out by another student, 

 I can here only treat this problem summarily and with regard to a few species. 



As has been pointed out before, Smaland is to a great extent uninhabitable 

 by the South Swedish steppe species. An account has been given on pp. 301 ff. 



