20 PLANTS OF NEW ZEALAND 



EPIPHYTES. 



"What a load 



That sturdy giant lifts in air ! 

 His mighty arms are strong and broad, 

 But all with alien growths are furred, 

 A shaggy hide of creepers rare ; 

 Their forks are all blocked up and blurred 

 With tufts of clogging parasites 

 That crowd till not a spot left bare 

 Might offer footing for a bird ! ' ' 



DOMETT. 



The epiphytes constitute another important plant guild. 

 These are plants which grow upon others, yet receive no 

 nourishment from them. They must be carefully distinguished 

 from parasites, with which they are often confused. The 

 parasite obtains its nourishment more or less completely from 

 the plant on which it grows. Some of the epiphytes, perhaps, 

 owe their existence to the same cause as the lianes. They 

 are plants which have assumed a habitat in the forks, or on the 

 branches of trees, in order to obtain more light ; but this 

 explanation will scarcely account for the New Zealand species, 

 as these, without exception, are occasionally found growing on 

 rocks. 



It is obvious that a plant which grows upon the bark of 

 a tree must often suffer from scarcity of water. Hence most 

 of our epiphytes have contrivances to protect them from 

 excessive transpiration. A plant, therefore, which can live 

 epiphytically, is also adapted for living on such a dry situation 

 as a rocky cliff. There, however, it may suffer from an excess 

 of sunshine. The physiological adaptations demanded by the 

 one situation are not necessarily quite the same as those 

 required for the other. Hence, though most epiphytes are 

 more or less commonly found growing on rocks, the converse 

 is by no means true. 



Epiphytes, like lianes, are generally supposed to be the 

 mark of a tropical climate. In Great Britain epiphytical 



