2 218. The Plant Formations of the High Mountains. 
Where there is an actual belt above the forest, it gradually decreases in height 
as one proceeds upwards and eventually ends in low bushes hugging the 
. ground, herb-field or fell-field cutting gaps into the association. Scrub is taller 
in gullies than elsewhere and on their shaded side attains its maximum height. 
‚The following are the principal classes of subalpine scrub based on the domi- 
nance of distinctive growth-forms. Though distinct enough in typical examples, 
 intermediates referable to more than one class are common. 
«@) Shrub-composite scrub; 
One or more of the tree-like species of Olearia or Senecio is dominant. “ 
Various divaricating-shrubs (spp. of Coprosma, Aristotelia fruticosa, Pittosporum 
divaricatum, Suttonia divaricata) will be present. Also one or other of the 
fastigiate species. of Dracophyllum, Phormium Cookianum, Cassinia Vawil- 
liersü, Phyllocladus alpinus, Nothopanax Colensoi and one or two species of 
Veronica are frequent members and Dracophyllum, Be Cassinia or 
even Veronica ‚may in places dominate, _ 
ER The trunks of the tree-composites are prostrate and yet tree-like, their 
horizontal spread exceeding the height of the association. The divaricating- 
 shrubs greatl nsity. The roof will be fairly level but pierc- 
Ei ed here, 22 there eby Dracophylium (Plate XLV, Fig.64). Shrub-composite scrub 
| a high rainfall for its full development. In the North Island, it occurs. 
on angi, Be Ruahine and Tararua Mts. and Mt. Egmont. In the South 
: Island, i it i re  characteristic feature of the Western botanical district on both 
i sides of the, ‚Divide, making, in many places, a broad belt above the forest 
as IR (1869. J: 4) and BUCHANAN ( 1869: 30‘) similar scrub De on the western , 
y sr of the Fiord district; it is also highly developed in Stewart Island. In 
DR what follows an ra is made to give some Be of the chief floristic cha- 
are: — 0. nenmularifoti, 0. Colensoi t 
aa er ich: 
