56 NEW ZEALAND PLANTS. 
Clematis have male and female flowers on separate plants, the male 
being much the more showy (fig. 4).:. The New Zealand passion-flower 
(Tetrapathaea australis) is another tendril-climber, the tendrils in this 
case being modified flowering-shoots. In autumn its orange or red 
fruits, containing numerous black seeds, are very showy. It is not 
found in every lowland forest, nor does it extend farther south than 
Banks Peninsula. 
All the lianes are worthy of the closest study, and not the least 
interesting point is to observe the differences between the climbing 
and non-climbing shoots (see text-fig., p. 52). Also, it is remark- 
able how certain species, such as some of the lawyers, the leafless 
clematis, the small-leaved pohuehue, and Metrosideros scandens, are 
lianes under one set of conditions and virtually shrubs under another. 
It is interesting, too, to grow this class of plants from seed, and 
to observe how the climbing habit is not shown at all, or very 
little, by the seedling at an early stage of development. 
Another method by which plants seek the light is to boldly leave 
the ground and perch high on the trees. Most instructive transitions 
between this perching habit and the ordinary method of growth may 
be observed in any New Zealand forest. The perching-lilies (Astelia) 
also grow on rocks or form huge tussock-like clumps on the ground. 
Many ferns live indifferently either on trees or the forest-floor, 
as does also the lovely forest tree-groundsel (Senecio Kirkit). 
Certain plants are almost exclusively perchers (epiphytic). Thus 
the perching-kohuhu (P2ttosporwm cornifolium) and the thick-leaved 
kohuhu (P. Kirkii) are of this class, and it is interesting that all the 
other members of the genus are ordinary terrestrial trees or shrubs. 
The puka (Griselima lucida), with its great leathery shining green 
leaves, is frequent high up in the forks of some forest giant ; 
but it also grows on rocks near the sea, and under cultivation 
makes a most handsome shrub for the open border. Some of the 
orchids are perching-plants—e.g., the common dendrobe (Dendrobium 
Cunninghamu)—and these have a special root-tissue which is quite 
spongy, and can absorb whatever moisture drips on to it. Some 
of these perching-plants build up great spongy masses of soil on the 
tree-trunks, and it is the water-holding capacity of this soil which in 
part enables epiphytes in general to live under what appear such 
adverse circumstances. Certain ferns and lycopods are generally 
epiphytic —e.g., a variety of the drooping-spleenwort (Aspleniwm 
