DEREN EEE 
Dune, 73 
of Apium, Crantzia linearis, Samolus repens var. procumbens, Selliera, Suaeda 
maritima, Leptocarpus and Scirpus nodosus may be all common. In the southern 
botanical province, Scirpus aucklandicus and Arge moschata are frequent, 
this latter extending to the northern shore of Cook Strait. Where the rock-x 
floor is dry, and at some distance from the sea in a Central botanical pro- 
Cassinia leptophylla and low bushes of Muehlenbeckia complexa are 
vince, 
common. Mariscus ustulatus is abundant where water lies. 
7. Dune. 
a. General. 
Not less than 127000 hectares of the coast-lands consist of dunes, which, 
in some places, extend inland for a distance of ı2 km. The most extensive 
areas are on the W. coast of the North Island, but considerable dunes also 
occur on the E. and N. In the South Island and. Stewart es the area, . 
9700 hectares, is still considerable. 
The plant-covering of the dunes is fairly uniform throughout New Zealand, 
the Lord Auckland and Kermadec Islands excepted, but certain latitudinall 
changes are evident due partly to climatic and partly to historical causes. 
Scirpus frondosus, Calamagrostis Billardieri, Festuca littoralis, Euphorbia glawa 
and Coprosma acerosa occur on all-unstable dunes. On the other hand, Sp- 
nifex hirsutus hardly extends beyond the Central botanical province. The 
three ecologically equivalent species of Cassinia (retorta, leptophylla and ful- 
vida) are each, in the order named, the dominant, or sole form, in the Northern, 
Central and Southern botanical provinces, ZPimelea arenaria, common on 
dunes in both the main En is SEN in the South Due distriet and 
in many are the associations are | virtually 
utilised ; as Sersang Erin, the SEEOHNS, inoR ii 
