8 



Göte Turesson 



Upper part of talus formation (65 m. — ^70 m.) 



Anthoxanthum odoratum * Juiiiperus communis 

 Athyrium filix mas Pohjpodium vîdgare 



Carex arenaria * Prunus spinosa 



* Fragaria vesca Ruhus fruticosus 



* Geranium robertianum * Vicia cracca 



* Linaria vulgaris 



Epilittoral belt. 



In determining the composition of the vegetation in this belt and tlie frequency 



ol: the different species the valence method of Raunki^r (Raunkiäir 21; see also 

 Smith 24) was used. 



Festuea ovina 50 



Hieracium pilosella 46 



* Achillea millefolium 20 



* Galium verum 20 



Lunula campestris 19 



* Lotus corniculatus 17 



Carex arenaria (sterile) 14 



Carex glauca 7 



Anthoxanthum odoratum 7 



Calluna vulgaris 7 



Aira prœcox 5 



* Thymus serpyllum 4 



Armeria vidgar is 3 



* Poly gala vulgaris 3 



Rumex acetosella \ 3 



* Trifolium repens 2 



* Viola canin a 2 



Antennaria dioica I 



* Galium saxatile 1 



* Leontodon autumnalis 1 



* Prunus spinosa 1 



Sedum acre 1 



Viola tricolor 1 



In addition the following species were found within the selected area (about 

 10X10 m.): * Carlina vulgaris, * Circium acaule, * Fragaria vesca, * Juniperus com- 

 munis, * Plantago lanceolata, * Potentilla erecta. 



Plagiotropy is characteristic not only of true maritime plants but also of plants 

 growing in the epilittoral belts and in the talus formation, as may be seen from 

 the plants listed above. The latter locality is particularly rich in plagiotropic plants. 

 The stems are as a rule erect between the stones, but on leaving the crevices they 

 become suddenly horizontally expanded. However, plagiotropy is more pronounced 

 than anywhere else on sandy beaches where the vegetation is open and scattered. 

 Individuals of Atriplex (see fig. 2), Chenopodium, Matricaria (fig. 3), and Polygonum 

 (fig. 3) lie here with their stems pressed against the substratum; only their tips 

 are directed upwards, and these do not rise more than a few centimetres above 

 the ground. 



Before going any further into the nature and cause of plagiotropy in mari- 

 time shore plants it becomes necessary to consider the theories that have been 

 advanced to explain the phenomenon, and to discuss the littérature on the subject. 



