Cockayne. — On Subalpine Scrub of Mount Fyffe. 363 



2. General Remarks on the Subalpine Scrub of New 



Zealand. 



Before proceeding with the details of the subalpine scrub of 

 Mount Fyffe, some general remarks on this plant formation 

 and its allied formations in New Zealand as a whole do not 

 seem out of place. 



To the various associations of shrubs which are so fre- 

 quently met with at all altitudes from sea-level to the sub- 

 alpine region the New Zealand colonists give the name " scrub." 

 And no word can better express the character of such assem- 

 blages, the members of which are of an extremely dense habit 

 of growth, with stiff or wiry interlacing or divaricating branches, 

 seemingly bearing the impress of countless furious gales. Such 

 scrubs are usually related, both ecologically and floristically. 



Characteristic stations are the sea-coast between forest and 

 sea-shore (coastal scrub), river terraces in the montane region, 

 and fans of rivers issuing from mountain torrents (terrace scrub 

 and in some cases river-bed scrub), stony beds of glacier rivers 

 near their source, moraines, and the upper margin of the sub- 

 alpine forest, where the scrub forms a compact and dense belt 

 between the forest and the subalpine meadow. It is to the 

 three last categories that the term " subalpine scrub "* is here 

 applied. Such a formation is not to be encountered on all 

 New Zealand mountains. It is found in greatest perfection on 

 those where the rainfall is excessive and the rainy days numerous, 

 while where the driest conditions prevail it may be whollv 

 wanting, or restricted to a few sheltered spots such as gullies 

 or moist hollows. 



Ecologically the subalpine scrub consists of shrubs or low 

 trees, with one exception evergreen, and usually of a xerophytic 

 character. Amongst the more common adaptations of these 

 shrubs are the following : (a) Dense habit of growth, with 

 much-interlaciug branches and small leaves ; (b) coriaceous 

 hard and stiff leaves, very frequently clothed with tomentum 

 on their under surface ; (c) vertical needle-shaped leaves at 

 the extremities of stiff, erect, naked branches ; (d) leaves 



* In the English translation of Schimper's " Plant Geography," p. 761. 

 this formation is termed " elfin- wood and shrub," a by-no-means happy 

 rendering of the German Krummholtz und Gestrauch. It seems to me 

 that the term " subalpine scrub " is much more expressive. As for the 

 Krummholtz. it is represented in New Zealand chiefly by the stunted trees 

 which sometimes form the upper zone of a subalpine forest, and of which 

 Noihofagus cliff ortioidcs, only a meter or so in height, is an excellent 

 example. Such, if they occur in company with other shrubs, I should 

 include in the subalpine scrub. Diels also translated Knieholtz as " sub- 

 alpine scrub" (" Vegetations-Biologie von Neu-Seeland." p. 261). 



