General Observations. 47 
5 
2 more extend almost from the N. of the North Island to Foveaux Strait, and 
of 3 with their northern limit in the S. of the Northern province 2 reach 
N. Otago and ı Foveaux Strait. 
The distribution of the remaining coastal species is as follows: Thirty-four 
are confined to the Northern and Central provinces, ı3 of which occur 
throughout or nearly so, ı6 do not pass beyond the N. of the Central pro- 
vince and the remaining 5 are of restricted distribution. Fourteen species are 
confined to the Central and Southern provinces but only ı occurs throughout. 
Four species which are common in Stewart Island extend just across Cook 
Strait by way of the west coast of the South Island, ı only gains northern 
Marlborough, 3 extend from the East Cape to the centre of the Southern 
province and ı occurs from southern Wellington to Banks Peninsula on the east. 
%. General Ecology of the Coastal Vegetation. 
The special conditions to which coastal plants are subject consist of a 
greater amount of salt in the soil than ordinary land-plants can tolerate, ex- 
posure to salt-laden winds which are frequently both violent and of long 
duration and, in some stations, strong insolation. The coastal climate is gene- 
rally uniform; frost is absent in the Northern botanical province and but trifling 
in the Central while in the Southern too it is of little moment, except on the 
‚coast of the Canterbury Plain where it may reach — 7°C. Excess of salt‘ in 
the soil and salt-laden winds are by far the more important of the above 
factors, and on such depend the characteristic coastal formations and the 
adaptations or capabilities of the species, At the same time, a salt soil is 
frequently absent, as on dune-areas where the power to tolerat salt winds or 
indeed violent wind in general is a matter of prime moment. From the above 
it follows that ground subject to flooding with brackish water or to frequent 
ia an BF sea-spray | is the chief home of ee er that other form ation ; 
