ADAPTATIONS OF GRASSLAND PLANTS. 89 
the centre of which rises the huge stout flower - stalk furnished 
with similar but much smaller leaves, the small whitish carrot-like 
bunches of flowers arismg from their junction with the flower-stalk 
(fig. 56). So rigid are the leaves that they are almost motionless in 
a heavy gale. Hven yet this remarkable plant is common in the 
the mountains, as in the Hooker Valley; but its numbers have 
greatly decreased since the early days, owing to the attacks of rabbits, 
hares, fire, and even sheep. The horseman now can ride through 
his sheep-run without being troubled by this formidable plant; also, 
it has a natural enemy—a beetle—which feeds upon its leaves. 
This special form of the Aciphylla, that of the tussock-grasses, 
that of the wild-irishman, that of the flat-stemmed leafiess brooms, 
that of the little heath, are all suited for reducing the plants’ demand 
for water in a dwelling-place where that essential commodity may 
at times be rather short. The frequent winds, with their great 
evaporating-power ; the hot sun of the summer; the stony nature 
of the ground ; as also the cold of winter, which may render the soil- 
water of no use to the plant—all these things and others demand 
drought-resisting structure in the plants. On the other hand, many 
of the small members of the association are not so well equipped 
to resist drought, nor do they need such an adaptation, but, safe 
from wind and sun in the shelter of the tussocks, they live in 
security. In other words, the well-being of the tussock-community 
depends upon the tussocks themselves, just as the delicate forest- 
ferns depend for their very existence on the tall trees which give 
them shade and shelter. Also, it must not be forgotten that both 
the drought - resisting structure and that which cannot tolerate 
desiccation are equally adaptations when each performs its special 
function. 
A very common feature of many parts of New Zealand, especially 
in the mountainous areas, is a broad shingly river-bed, bounded on 
either side by high terraces, or sometimes fillimg up a narrow valley. 
The water of these rivers is not usually confined to one channel, but 
meanders in several streams over the wide stony bed (fig. 55), which 
im consequence is in places quite dry and ready for plant colonists. 
These are not slow to avail themselves of the chance to “take up 
land,” and, like their confréres of Tarawera, engage the wind or the 
birds to convey them to their new holdings, while some even travel 
by water. 
