ne 
® 
234 The Plant Formations of the High Mountains. 
are much the same as those of low tussock steppe for the same locality. 
Since D. Raoulii is less relished by grazing animals than other tussock-grasses, 
. its present distribution may in some instances not be a natural one. 
3. Mountain tussock (Danthonia flavescens) Steppe. 
‚Danthonia flavescens is a more robust and broader-leaved grass than 
D. Raoulii and forms large tussocks up to 1.5 m high, or more. The asso- 
ciation, when fully developed, may consist of little else than a dense green 
mass of tussocks not easy to penetrate. This has led to the destruction of 
the original association in many places through periodical burning by musterers. 
in order to make paths for bringing down the sheep from the alpine pastures. 
At the present time, the tussock-grassland under consideration is to be seen 
„at its best on the wet mountains of the South Island, especially in the South 
"Otago botanical district. But even on the much drier mountains of the North 
Otago district it is not wanting. 
 Usually Danthonia Ravescens steppe forms a belt commencing at from 900 
to 1250 m altitude and extending upwards for some 300 m more or less, when 
it may be succeeded, on certain mountains, by low tussock steppe composed 
principally of Poa intermedia. In some localities, however, an association with 
D. flavescens dominant occurred in primitive New Zealand at a much lower 
‚altitude. Thus, on the table-land extending from the Lammermoor Mountains 
to the ‚gorge of the R. Taieri (with a maximum’ altitude of 600 m) there is 
every indication that most of the surface was occupied by D. Hlavescens accom- 
panied by abundance of Aciphylla Colensoi. As a good example of the tall 
tussock steppe now being considered that of the Hector Mountains (South Otago 
district) may cited. The tall tussock belt begins at about rı00 m altitude. 
In many places the tussock is extremely dense. Acıphylla Colensoi is abundant; 
there is a good deal of Chrysodactron Hookeri. The following species are fairly 
common: Calamagrostis avenoides, Agrostis Dyeri, Poa intermedia, Festuca 
novae-zelandiae, Gentiana corymbifera (or an allied species), Wahlenbergia albo- 
marginata, Celmisia coriacea, C. Lyallii and Helichrysum bellidioides. Atits : 
upper limit (1320 m) the Danthonia tussocks become scattered and oa inter- 
media becomes dominant, while many of the higher-mountain plants put inan 
appearance, e. g.: Carer wakatipu, Eptlobium. Tasmanicum, Coprosma FEERES a 
 Phyllachne ER and Raoulia grandifiora. * 
es winter, notwithstanding® the great size of the onen kübssaks they. 
are flattened to the ground by the snow and are EN not ge 
until the, ze of December, or even later. 
Bo | Kane De association. | es 
a) Diode exigua steppe. T. exigua is a small neh, grass sprea- 
ding er by means of its long, much-branching rhizomes which form 
‚a matted tangle. The leaves are narrow, about 2.5 cm long, filiform, stift and 
Vhere d close, dense sward looking al- 
almost DR | 
