166 The Plant Formations. 
donta, OÖ. arborescens, and as undergrowth — Polystchum vestitum, Blechnum 
El, B. fluviatile and B. penna-marina. 
4. River-bed forest. 
This occurs only in the Western district and is in harmony with the 
climate, which is antagonistic to steppe. The tree-community consists in part 
of. species not common in the adjacent rain-forest, e. g. — Rubus schmidelioides 
var. coloratus, Coriaria ruscifola, Pennantia corymbosa, Arıstotelia racemosa 
and Plagianthus betulinus. 
The ground is level and traversed by numerous streams. The upper 'soil 
consists of humus beneath which is merely river-shingle.. The vegetation is 
in three layers, — the fioor-plants, the small tree-ferns and shrubs and the low 
trees. The association is 4.56 m tall and of close growth. Slender tree- 
trunks not exceeding ı5 cm in diam. are the rule; they may be erect or more 
or less leaning and draped with a moss-mantle while from their branches hangs 
the pale moss Weymouthia Billardieri. Coprosma rotundifolia, usually a shrub, 
is the dominant small tree, and it grows in such profusion at times as to make 
pure stands. Besides the already-mentioned trees, the following are common: 
— Carpodetus serratus, Melicytus ramiflorus, Fuchsia excorticata, Pseudopanax 
r crassifolium var. unfoliatum and Griselinia littoralis. Stunted Podocarpus totara 
00. and Weinmannia racemosa may oecur. 
The second tier consists of young forest-trees, the Coprosma-form Be 
inating, together with small Dzcksonia squarrosa and Femitelia Smithii and me 
semi-tree-ferns Polystichum vestitum and Dryopteris Pennigera. 
On the floor are mosses, liverworts, the liane Metrosideros Iyperieifol 
(creeping), Blechnum capense and B. fluviatile. 
5: The lianes Rudus schmidelioides var. coloratus, Mitsosikerös Anpericifoli 
u and Polypodium diversifolium are common, the two latter especially abund: 
on tree-fern stems. The filmy ferns, Hymenophylium scabrum, H. sanguinolen- 
tum and Trichomanes. reniforme cover the leaning trunks, particularl; 
 Griselinia Üttoralis. Polypodium grammitidis, : Billardie! and the | o 
zarina mucronata are fairly common as epiphy tes. 
Aa altitude of some 300 m on river-bed in the Weiter district 
is an association closely allied. to subalpine totara forest (Plate XXXTI, Fig. . 
although that of the adjacent slopes is Weinmannia-Metrosideros. and tha 
ee ARE, acrydioides. ee 
Podocar, adus eins (a ee = Bean 
um are domi (Plate XXXI, Fig. 42) and Lidocedrus Bit 
The forest is oe the trees &c. are erect. The undergrowth 
f— - Polystichum vestitum, Frey divaricatum, Arisior 
mplex, N. alum, Cop 
» 
lu 
B 
