4'2 PLANTS OF NEW ZKALAND 



Plants wliieli liave been evolved in soils containing more 

 than a. half_/jf;- ci'iit. of salts in S(jlution, are termed lialophijtes. 

 Such [)hints a.re fomid ehieti\' near the sea-shore, b)' river 

 estuaries, or in salt marshes. They sometmies occur also in 

 desert a.reas, particularly in the dried-up beds of salt lakes. 

 They often bear resemblances to xero[)hytes. The water of 

 salt-mea.dows is apparently not readily absorbed Ijy plairts, and 

 conse(]uenth- such situations may be physiologically dry. 

 Probably the })resence of salts in solution interferes with the 

 passage of moisture by osmosis iirto the plant cells. A fuller 

 consideration oi the structure of halophytes will be fouird under 

 the family Cheno[)odiaceae. 



Hjidrophytes are plants which have been produced amidst 

 abundance of water of moderate temperature, and in the 

 absence of an excessive amount of dissolved salts. They will 

 be further considered under Myriophi/Uum. Mesopliytes, 

 on the other hand, are [)lants whose structure indicates that 

 they have been developed m intermediate conditions, where 

 there was neither saturation with moisture, nor was there 

 drought. Mesophytes frequently lose their leaves at the end 

 of the growing season, and often die back to the ground. 

 Amongst them are a large number of annuals, bulbous, and 

 tuberous plants. New Zealand has remarkably few mesopliytes. 

 Trees such as Eutelea &nA Arisiotelia /■«c(';«o-Srt are mesopliytic, 

 but dic<.)tyledonous herbaceous mesophytes are almost com- 

 pletely absent from New Zealand. We have scarcely any 

 annuals, and very few bulbous plants. It is due to lack of 

 them tliat our lowland pastures and hedgerows do not display 

 in S[)ring and early summer such brightness of colour as is 

 to Ije seen m many other lands. 



