126 



Transactions. — Botany, 



ing such small tracts as are sheltered by river-terraces. The 

 only other shelter is from the few plantations of exotic trees — 

 mostly Pinus insignis and Eucalyptus globulus — and gorse 

 hedges which have been planted by the settlers. The vege- 

 tation may be divided primarily into the following plant-for- 

 mations : — 



Name of Plant-formation. 



Most Characteristic Plant. 



1. The moving sand-dune 



2. The fixed sand-dune . 



3. The salt meadow 



4. The flowing water 



5. The brackish water 



6. The lowland swamp 



7. The lowland forest 



8. The grassy meadow 



9. The stony river-bed 



DesmoscJuxmis spiralis. 

 Discaria toumatou. 

 Plagiaiithits divaricatus. 

 Myriophyllum elatinoides. 

 Zoster a nana. 

 Phormium tenax. 

 Podocarpics dacrydioides. 



n 



Raoulia tenuica.ulis. 



Besides the above formations, several minor divisions will be 

 treated of. It is not always easy to select the most charac- 

 teristic plant ; cases frequently occur in which various plants 

 could be chosen with equal propriety. 



(2.) The Lower Mountain Region : This varies in altitude 

 from 457 m. to 761m., and includes the foot-hills of Mount 

 Torlesse and Mount Puketeraki (in part) ; the whole of the 

 table-land, including the Trelissick basin, where it ascends to 

 over 900 m., also the valleys of the Esk, Poulter, and Upper 

 Waimakariri to about 761m. The climate of this subregion 

 may be gathered from what has gone before, and varies from 

 extremely dry in the Trelissick basin and vicinity of the Mount 

 White homestead to very wet with many rainy days and a 

 considerable amount of fog and cloud at its junction with tlie 

 western climatic region. The ground is mostly extremely 

 stony, consisting of a great depth of stones, sometimes quite 

 without soil, and repeating on the river-terrace slopes the 

 shingle-slips of the higher levels in miniature. With the 

 exception of the Trelissick basin the whole of this subregion is 

 wetter than the lowland subregion, but the loss of water in 

 the soil, owing to the great depth and slope of the stony 

 ground, is much more rapid. Swampy ground is of frequent 

 occurrence, and streams are abundant. Before joining a main 

 river the tributaries usually stretch out into huge fans, with 

 remains of older fans bounding them. On such a fan coming 



• This formation will bo subdivided into several minor formations, 

 each with a different characteristic plant, depending in large measure 

 upon the depth of the soil. Large stretches of very stony, arid, barren 

 land are occupied by Lcptospermnm scoparium, especially towards the 

 centre of the Canterbury Plain, on the north bank of the river. 



