River-bed. 165 
Rıver-bed dune. 
Low isolated dunes, or short ridges, are frequent here and there on river- 
bed. They are simply collections of the blown sand and silt. Usually they 
are fixed by vegetation. The small tree Sopkora microphylla was originally 
common. Phormium tenax, Arundo conspicua and Cassinia Julvida are abun- 
dant. The species of Raonlia are generally absent. The introduced Zupinus 
arboreus has complete possession in some localities. | 
Groves of trees &c. 
In some places, even yet, small groves of trees are to be met with, 
especially at the base of a high terrace. Sophora microphylla will be do- 
minant, accompanied probably by Cordyline australis, Pittosporum tenuifolium, 
Melicytus ramiflorus, Fuchsia excorticata, Nothopanax arboreum and Griselinia 
littoralis, while Rubus australis, Muehlenbeckia australis and Parsonsia hetero- 
fhylla may be abundant as lianes loading the trees with greenery. 
Phormium-Arundo-Cordyline swamp and slowly-flowing streams or ponds 
with aquatic and swamp vegetation are common enough on river-beds, but 
they are identical with similar associations elsewhere and need no description. 
2. Western river-bed. 
The station is less xerophytic than eastern river-bed and so many of the 
most xerophytic species are absent, e. g. —: Raoulia lutescens, R. Monroi, the 
dwarf species of Carmichaelia, Muehlenbeckia ephedroides, Discaria toumatou, 
Cassina Julvida and Scleranthus biflorus. Though open in many places, the 
vegetation may be closed. 
e following are the most important ee — (arex comans, Muchlen- 
beckia axıllaris, Ranunculus foliosus (sometimes), Acaena Sanguisorbae (var. 
with silvery leaf), A. inermis, Coriaria ruscifolia, C. thymifolia, Pimelea pro- 
strata var. repens, Epilobium pedunculare, Hydrocotyle novae-zelandiae, Mazus 
radıcans (very characteristic of Westland river-bed), Veronica Lyallii (com- 
mon in montane belt, but rare at sea-level), Coprosma rugosa, C. brunnea, 
Nertera depressa, Wahlenbergia albomarginata, Pratia angulata, Helichrysum 
filicaule, H, bellidioides, Cotula squalida, Raoulia glabra (sometimes), R. au- 
Stralis, R. tenuicaulıs. 
3. Western river-terrace scrub. 
On older iveriad and on the face of terrace there is in the Western 
district an association closely allied to subalpine scrub but with the members 
Much more erect and.not tangled. The following are the principal species: 
— Podocarpus totara, Muehlenbeckia australis (liane), Rubus schmidelioides var. 
 £oloratus (liane), RT paludosa, Coriaria ruscifolia, Aristotelia Fruti- 
. 05a, A. Colensoi, Plagianthus betulinus, Nothopanax. Colensoi, N. parvum 
 Fseudopanax. crassifolium, Griselinia littoralis,. Veronica ee er, 
5 ma = ee, c a Garia mine else . tlieifolia, O.macro- 
