206 The Plant Formations of the High Mountains. 
tioned species may be present and, in addition, others according to the geo- 
graphical position of the forest. Wet mountain-beech forest occurs on the W. 
and S. of Ruapehu and at many points on the eastern slopes of the Southern 
Alps, within the limits of the western rainfall. 
On Ruapehu, there is a certain amount of Zidocedrus Bidwillii; tussocks 
of Gahnia paucifliora are common. Enargea parviflora, Libertia pulchella, Sty- 
phelia fasciculata and Myrtus pedunculata (these two latter prostrate), are abun- 
dant, as also Gleichenia Cunninghamii, in some places. 
Fig. 57. The epiphytic moss Weymouthia Billardieri hanging from twigs of Gaya Lyallü — 
Clinton Valley, Fiord bot. distr. at 600 m alt. Photo L. Cockayne. 
The Waimakariri Basin contains an extensive area of this association. Here 
Gaya Lyalliüi is a striking feature, not only when white with blossom, but from 
the tender green of its leaves in spring and summer and their beautiful yellow 
coloration in the autumn. 
3. Silver-beech (Nothofagus Menziesii) forest. 
General, 
This association is common on the North Island dividing range, the Volcanic 
Plateau, North-western, Fiord and South-Otago districts, but it cannot tolerate 
a steppe-climate. Besides the dominant N. Menziesii, N. fusca and N. cliffortioides 
are present in some localities, as also the rain-forest trees, Zidocedrus Bidwillii, 
