124 TRANSACTIONS OF THE [Suss. LXXv. 
(Thymeleac.), occasional plants of Angelica Gingidiwm 
(Umbel.), with its tufted, coriaceous pale-green leaves, 
small colonies of Veronica Bidwillii, the grasses Festwea 
rubra var., and Hierochloe Fraseri, Geranvum sessiliflorwm, 
Wahlenbergia saxicola, and Viola Cunninghamn. 
Raoulia Haastii cushions are still present, but in much 
smaller quantity, but their remains in various stages of 
decay are, in places, much in evidence. On the oldest 
river-bed there is abundance of Acwna Sanguisorbe var. 
pilosa (Rosac.) and A. imermis, and as the scrub is 
approached Geranium microphyllum becomes extremely 
common. 
As for erect shrubs, plenty of stunted Coprosma rugosa 
is dotted about, and the spiny Discaria towmatou 
(Rhamnac.) is frequent in many places. 
y. Serub. 
Serub is the final association, so far as the river Rakaia is 
concerned. On other river-beds Nothofagus forest may be 
the climax, but it is generally on slopes or the summits of 
high terraces that forest occurs. 
The scrub is simply subalpine scrub which has descended 
to the river-bed, and so needs no detailed description. It 
consists of: Gaya Lyallii (Malvac.), Olearva iierfolia, 
O. avicennicefolia, Senecio eleagnifoliws (Compos.), Phyllo- 
cladus alpinus (Paxac.), Coprosma propinqua (?), C. rugosa, 
C. parviflora (Rubiac.), Discaria toumatow (Rhaumnac.), 
Veronica subalpina, V. salicifolia (Serophular.), and 
OCoriaria racemosa (Coriariac.). As lanes there are 
Rubus schmidelioides var. coloratus (Rosac.) and Clematis 
australis (Ranun. _). 
Discaria scrub, or perhaps better Discaria steppe, is quite 
distinct from the above. It frequently occurs at a much 
lower elevation, and probably is not a phase of the succes- 
sion, as here described, but a primary formation depending 
on a certain stability of the river-bed. It is especially 
plentiful on the fans of tributary streams, and makes 
quite a dense scrub not easy to penetrate on account of its 
formidable thorns. Discaria is the sole component; 
the dark colour of its stems and its few leaves render the 
association conspicuous, even from a distance. 
