298 RIKARDSTERNER 



no forest can grow (a lake surface, a large watercourse or a fen), they may be 

 sufficiently exposed. 



This herbaceous hillside flora would seem to be richest and to have its greatest 

 distribution on the rocky pavements of Oland a7id Gotland. The inconsiderable 

 thickness of the soil in conjunction with the scanty precipitation does not here 

 allow of the existence of a shading forest layer. In the comparatively large 

 sandy areas in the precipitationless regions in the most south-easterly part of 

 Sweden, especially in the vicinity of the seashore, herbaceous sand-grass heaths 

 ought to have their natural place of abode. Among suitable exposed hill- 

 sides, the calcareous slopes in parts of Vdstergdtland (especially Falbygden), 

 Osterg'dtlarid (the western part of the plain), and Skane (at least the north- 

 eastern part) would in the first place seem to be taken into consideration. Thick 

 moraines, oses and hilly tracts here form dry, steep slopes, where a more closed 

 and shading forest layer may be supposed to be excluded without the inter- 

 vention of man. With regard to Vastergotland minor »Alvar-pavement» areas 

 may also be added. In sundry places in other parts of South Sweden there are 

 steep slopes of ))oses>-> in the ground vegetation of which xerophilous and helio- 

 philous species may probably exist without human interference, especially if the 

 slope faces an unwooded country. Lastly we have to consider southerly exposed 

 hillsides on shores and rocky escarpments. 



The steppe flora has a remarkably great number of representatives in the 

 xerophilous herb-grass communities that are thickly spread on Oland and Got- 

 land on rock-pavement or as sand-field vegetation. 



Of the South Swedish steppe species only the following are lacking on Oland: 

 Allium montanum, Inula ensifolia, Oxytropis pilosa, Potentilla rupestris, Pulsatilla 

 patens, Senecio integrifolius, Silene viscosa (which has, however, been observed 

 on the island once in the past), and Stipa pennata. 



On Gotland the following are missing: Allium montanum, Artemisia laciniata, 

 Bassia hirsuta, Carex ligerica and obtusata, Inula ensifolia (note, however, the 

 occurrence on Gotland of I. vrabelyiana Kern., a hybridogenous transition type 

 between I. ensifolia and salicina. Cf. Lindm.an, »Botaniska Notiser» 19 lO, pp. 31 

 ff.), Koeleria glauca (found on Gotska Sandon by Sernander 1893, cf. K. 

 Johansson 19 10), Peucedanum oreoselinum, Plantago tenuiflora, Potentilla rupestris, 

 Ranunculus illyricus, Senecio integrifolius, Silene viscosa (seen once on Stora 

 Karlso; Sernander 1894, p. 92), and Stipa pennata. 



Falbygden in Vastergotland is known of old for its peculiar flora, which is 

 to a great part caused by the occurrences of steppe species. An account of the 

 geographical conditions of Falbygden and of the unique flora on its numerous 



