184 



Furthermore the fresh-water-vegetation shows us, that 

 the North-Frisian Islands are closely allied with West-Jut- 

 land. Of plants living in or by freshwater, the following 

 are found on the North- Frisian Islands and most of them 

 are common in West-Jutland, while the East-Frisian possess 

 none of them and only a few are found on the West-Frisian 

 Islands : 



Butomus umbellcttus Batrachium heterophyllum 



Potamogeton obtusifoUus Ranunculus Lingua 

 Scirpus fluitans Nymphaea alba 



Rumex Hydrolapathum 



Batrachium hederaceum 

 — circinnatum 

 I would here add a few words about Subularia aqua- 

 tica. This plant which in Denmark is only to be found , 

 in West- Jutland at Agger, in Skjern stream, at Ørnsø near 

 Ribe and at Røddinggaard, I have found growing luxuri- 

 antly in a somewhat dry sandhill-lake south of the ligt- 

 house on Amrum. In the southern part of the continent 

 Subularia aquatica is only found in a few places in the 

 interior of Germany and in one locality in Belgium (Gam- 

 pinen). 



The North-Frisian Islands are more closely connected 

 with West- Jutland by the vegetation on the drift than by 

 any of the above vegetation-formations, and at the same 

 time they distinctly differ from the East- and West-Frisian 

 Islands upon which the primary, unchanged Dilluvium only 

 reaches the surface on a few spots. 



Some plants distinctly local to the drift in West-Jut- 

 land of which the greater number are common on the 

 North-Frisian Islands but have never yet been found on 



lacustris 



Nuphar luteum 

 Subidaria aquatica 

 Slum latifolium 

 Cicuta virosa 

 Helosciadium repens 

 Hottonia palustris. 



Glyceria spectabilis 

 Digr aphis arundinacea 

 Iris Pseudacorus 

 Sparganium ramosum 



simplex 



