THE VEGETATION OF THE COAST. 63 



CHAPTER V. 



THE VEGETATION OF THE COAST. 



General remarks Adaptations of coastal plants Physical and physiological 

 dryness Plants of sandy and rocky shores Seaweeds Sandhills Reclam- 

 ation of dunes The wonderful mangrove Coastal shrubberies A natural 

 post-card The coastal veronica Vegetation of rocks and cliffs Salt 

 meadows and salt marshes Stephen Island, the home of the tuatara The 

 Three Kings and Poor Knights Islands. 



GENERAL REMARKS. 



A COAST-LINE between four and five thousand miles in length, extend- 

 ing from nearly the latitude of Sydney in the north to far beyond 

 that of the southernmost point of Tasmania in the south, may well 

 furnish a great deal of diversity in both species and societies of plants. 

 The varieties of stations for plant-life are also augmented by the 

 physical features of the shore. In some places calm fiords, flanked by 

 tow r ering, precipitous mountains, stretch far inland ; in others an iron- 

 bound coast faces the ocean storms. There are long stretches of level 

 shore of gravel or of sand extensive estuaries, and tidal rivers. In 

 short, the two main Islands, together with Stewart Island, present 

 a diversified coast not surpassed in variety of physical features by any 

 other of equal size. 



ADAPTATIONS OF COASTAL PLANTS. 



Latitude being left out of the question, in all parts of the world 

 coastal vegetation, both in its form and distribution, depends upon 

 certain factors. Of these, salt in the soil and exposure to sea-sprav 

 and violent winds are of prime importance. Wherever they occur, 

 genuine seaside plants have various features in common. The most 

 important of these are contrivances to regulate the water-supply, 

 the commonest of \vhich is succulence of leaf and stem, one or 

 both. This succulence is caused by the presence of special tissues 

 which serve for water-storage. Many New Zealand coastal plants 

 exhibit this feature. The ice-plant (Mescmbrijanthenmm australe, 

 pig's-face, horokaka), which so frequently drapes the coastal cliffs 



