WIND-SHRUBS. 17 
plant-geography, notwithstanding the accepted dictionary meaning 
of the word and the failure to bring home to the student the 
important fact that the so-called “ scrub” belongs to ‘ 
a scientific term of precision and general application. 
“ Scrubs,” in the sense used in this book, are the result of dry 
soil (frequently stony), high winds, wet swampy soil with a low 
‘ rain-forest,” 
oxygen content, the climate of high altitudes. and absence of a 
certain amount of sunshine, with the resulting “sour” soil; but 
these different factors need not all be present. 
On the hills near Wellington there was originally a good deal 
of scrub whose origin may be traced to wind alone. Some still 
exists on the Kaukau Range, at its junction with the Crow's Nest. 
This scrub is simply the adjacent semi-coastal rain-forest reduced 
to scrub under the dwarfing action of frequent gales, the wind also 
selecting the colonists, or, rather, killing out the unfit. In addition 
a species from the neighbouring rocks, Veronica parviflora—not in 
the original forest—has entered the community. Nor, being a small 
tree, has it been able to get rid of its trunk, which, if used, would 
make its new dwelling-place impossible to live in; consequently the 
trunk is got out of the way by being laid prostrate for many yards 
upon the ground. Very conspicuous in this scrub are the supra- 
divaricating whauwhaupaku (Nothopanax anomalum), and the three 
myrtles—the ramarama (Myrtus bullata), the rohutu (M. obcordata), 
and their hybrid, M. Ralphii. 
Another interesting wind-scrub occurs on the North Cape Pro- 
montory, where the tanekaha (Phyllocladus trichomanoides), usually 
a forest-tree 60 feet or so high, is dwarfed to 4 feet in height. 
In Westland extensive scrubs occur on the faces of the river- 
terraces of the lowland belt, and follow the river-valleys until they 
merge into the subalpine scrub of the high mountains ; indeed, the 
two associations are closely allied, containing as they do many of 
the same species. This terrace-scrub is not so dense as its subalpine 
relative. It consists of—the sharp-leaved totara (Podocarpus acuti- 
folius; the New Zealand holly (Olearia ilicifolia); the mountain- 
akeake (Olearia avicenniaefolia) ; the false New Zealand holly (Olearia 
macrodonta) (fig. 38); the lancewood (Pseudopanax crassifolium var. 
unifoliatum) ; the glossy karamu (Coprosma robusta); the mountain 
ivy-tree (Nothopanax Colensoi) ; the mountain-wineberry (Aristotelia 
fruticosa); various coprosmas of the divaricating form —e.g., the 
common coprosma (C. propinqua), the leafy coprosma (C. parviflora), 
