*254 PLANTS OF NEW ZEALAND 



cuticle and leaves rich in slime, show excellently how 

 dependent the mangroves are upon the dampness of the 

 atmosphere for their moisture. However, P. divaricatus, 

 though found at the head of tidal creeks and estuaries is really 

 a plant of the salt meadows, and not of the tidal flats, and can 

 .scarcely be termed a mangrove. 



Plagianthus betulinus (TJie Birch-like Bihhon-ivood). 



A tree, varying from 30ft. -60ft. in height, with terminal panicles of white 

 flowers. The young shrub forms a mass of tortuous interlacing branches. 

 Leaves lobed, or coarsely toothed. Petals rounded at the tips. North and 

 South Islands, Stewart Island, Chatham Islands. PI. Jan. -Feb. 



P. betulinus is readily distinguished from most of the other 

 denizens of the New Zealand forests by its softer leaves, 

 which resemble those of a deciduous tree, rather than those 

 of an evergreen. Indeed, in most localities of the South 

 Island, the plant does lose its leaves on the approach of 

 winter. It has obtained its specific name {betulinus) from the 

 resemblance of its foliage to that of the English birch. 

 Plagianthus, however, has much larger leaves than Betulus. 

 Owing to the presence of an inner, ribbon-like bark, it 

 is generally called the Ribbon-wood by the colonists. The 

 Maoris used this bark for making rope and twine for their 

 fishing nets. It also makes a good substitute for the Raphia, 

 used by gardeners in tying up soft plants. 



Strange Seedling Forms. 



The >Tjung stages of the [)lant are very different from 

 the older forms. An extraordinary proportion of New 

 Zealand trees and shrubs pass through one or more distinct 

 intermediate stages before reaching the adult form. In a 

 considerable number of cases (e.g. Pennantia corymbosa, 



