VEGETATION OF THE SEA-COAST 383 



The plant best able to withstand salt water is the Glass- 

 wort (Salicomia), which acts as a pioneer, but near the sea 

 the plants are few and occur only at wide intervals. The 

 Grasswrack (Zoster a marina) often occurs in quantity, and 

 is interesting in that it flowers under water, and has pollen- 

 grains which float in and are carried by water from the 

 anthers to the stigmas. Other plants generally met with 

 on the salt-marsh are the following : Sea Poa (Glyceria 

 maritima), Sea Arrow-grass (Triglochin maritimum), Sea 

 Aster (Aster Tripolium), Glasswort (Salicomia radicans), 

 Sea Oraches (Atriplex spp.), Sea Purslane (A. portulacoides) , 

 Sea Spurrey (Spergularia maritima), Sea Lavender (Limo- 

 nium vulgar e), Sea Plantain (Plantago maritima), Sea Blite 

 (Suaeda maritima), Scurvy- grass (Cochlearia officinalis) ; 

 and other species, e. g. Cochlearia anglica, Sea Rush 

 (Juncus maritimus), Sea Milkwort (Glaux maritima), Buck's- 

 horn Plantain (Plantago Coronopus), Sea Couch-grass 

 (Agropyron pungens) . 



These species vary much in distribution with the nature 

 of the ground, as to whether it is muddy or sandy ; low- 

 lying and wet ; or raised, exposed, and drier. The associa- 

 tions of plants occurring in these different parts of the salt- 

 marsh, together constitute the salt-marsh formation. 



Rock-plants. Many of these plants occur also on the 

 rocks of the coast, especially those washed by the spray. 

 The more characteristic are : Samphire (Crithmum mari- 

 timum), Sea Lavender (Limonium vulgar e), Buck's-horn 

 Plantain (Plantago Coronopus), Sea Pink (Statice maritima), 

 and Sea Campion (Silene maritima). 



Sand-dunes. If we examine the sand along the shore 

 which is subjected to the action of the waves, characteristic 

 ripples will be found on the surface ; but, in addition to 

 wave-ripples, other similar ripples may be seen, especially 

 on sand over which wind has blown for a few hours The 

 wind rolls the sand -grains before it and heaps them up in 



