364 Transactions. 



reduced to scale-like organs closely pressed against the shoot- 

 axis ; (e) recurving of leaf-margin. Many of the plants, too, 

 have aromatic leaves, and a number are hygrophytic in the 

 juvenile and xerophytic in the adult form. 



Floristically, the formation under consideration contains 

 a diverse assemblage of genera and orders made up of shrubby 

 veronicas, composites, epacrids, taxads, araliads, and rubi- 

 aceous plants, together with certain other shrubs such as Pittos- 

 porum rigidum* Aristotelia fruticosa, Suttonia divaricata, and 

 Gaya lyallii. Herbaceous subalpine and alpine plants grow 

 under the shelter of the shrubs, where these latter are not too 

 dense, while Phormium coolcianum and the giant umbellifer, 

 Aciphylla colensoi conspicua, when present, easily hold their 

 own with the arborescent vegetation. 



Such a belt of shrubs may vary much in breadth and height, 

 but it is always most difficult to penetrate, and in some places 

 is all but impassable, unless a track be cut through it. As for 

 the composition of its members, this is far from uniform for all 

 New Zealand mountains. Various plants are dominant in dif- 

 ferent regions, or even in adjacent scrubs. Thus, at the source 

 of the River Poulter in the Snowcup Mountains the physiognomy 

 of the adjacent scrubs is so entirely different that it is easy to 

 tell at a distance whether Gaya lyallii, Dracophyllum traversii, 

 or Phyllocladus alpinus are dominant. Also, the arrangement, 

 number, and proportion of the constituents vary in different 

 localities. As for the shrubs themselves, some belong exclu- 

 sively to the subalpine region,"}" such as Nothopanax lineare, 

 Olearia lacunosa, 0. illicifolia mollis, 0. excorticata, Veronica 

 hectori, V. subalpina, Senecio bidwillii, Dracophyllum traversii; 

 others again, such as Olearia illicifolia, Coprosma propinqua, 

 Cassinia vauvilliersii, Dracophyllum longifolium, and Notho- 

 panax colensoi, are common to all levels from the subalpine to 

 the sea ; while, finally, some others are especially plants of 

 " terrace scrub," such as a number of veronicas, including 

 V. cupressoides. 



Notwithstanding the special climatic and edaphic conditions 

 which govern the distribution of the subalpine-scrub vegetation, 



* Quite recently on the Tararua Mountains I saw the typical P. rigid inn. 

 Hook, f., growing in abundance. It seems to me quite distinct from the 

 above plant, which is common in many parts of the South Island, but 

 in this paper the usual identification may stand. 



t Of course, it is not impossible to find stray plants of any region in 

 one to which they do not properly belong. Thus I have observed the 

 truly subalpine and perhaps alpine Ranunculus lyallii at sea-level, Mil- 

 ford Sound, and Helichrysum, grandiceps at 400 m. in Westland ; but that 

 does not exclude those plants from being considered rightly as plants of a 

 much higher altitude. 



