374 Transactions. — Botany. 



with which they are associated,* since by virtue of their com- 

 paratively slender but extremely long stems they have to pos- 

 sess special adaptations in order to procure a sufficient supplv 

 of water for their leafy shoots high on the tree-tops. Thus, as 

 the forest trees gradually died, the lianes in question would be- 

 come dominant, and, uniting themselves with certain coastal 

 plants, and evading the wind by no longer climbing up aloft, 

 be able to maintain themselves in comparative luxuriance. 

 Leaving out of the question any xerophytic structure, this 

 power of certain lianes to assume a shrubby habit, through 

 the interlacing or twining of their shoots, gives them a great 

 advantage over forest trees when exposed to furious gales. 



Further evidence of the ancient forest formation is afforded 

 by the plants of Schefflera digitata and Metrosideros lucida. 

 Phormium tenax, Cordyline australis, and Arundo conspicua 

 would, on the contrary, be rather plants of the forest's out- 

 skirts, Phormium tenax especially occurring frequently as a belt 

 near high-water mark. 



Judging from the ordinary coastal plant-formations of south 

 Westland, there should appear nothing surprising in the Frey- 

 cinetia formation of the Open Bay Islands, insomuch as Frey- 

 cinetia in many places forms an outlier of the present forest 

 formation, in company with certain shrubs and low trees, grow- 

 ing very close indeed to the sea. Muehlenbeckia adpressa, too, 

 frequently remains as a somewhat ball-shaped bush of the open 

 where the forest has been cleared, and in some places it too 

 comes to high-water mark, as e.g. near Nugget Point, in Otago, 

 where, with the shrubby nettle, Urtica ferox, and certain ferns, 

 it forms dense thickets, probably in places where the forest has 

 been removed. Muehlenbeckia complexa, too, on the Port Hills, 

 Canterbury, and elsewhere, no longer a forest plant, forms dark- 

 coloured round or pyramidal shrubs, which are so frequent on 

 the tussock slopes as to give a peculiar physiognomy to the 

 landscape. Many other examples of lianes taking a shrub form 

 in the open after the removal of forest could be adduced, but 

 the above must suffice here. 



An interesting fact in the distribution of plants on the Open 

 Ray Islands, and one for which T can offer no adequate explana- 

 tion, is the non-occurrence of Freycinetia on the smaller island. 

 On the larger island, also, it does not occur on the smaller part. 

 It may be that in the struggle for existence the Muehlenbeckia 

 may have some slight advantage over the Freycinetia which 



* Thus Wanning writes: " Blattbau und Sprossbau eines Tcilcs <ler 

 Lianen erinnern an tlen Bau der Xerophyten." Lehrbuch dor okolo- 

 gischen pflanzengeographie, Zweite Auflage dor Dcutschen Ausgabe, 1002. 

 p. 110. 



