Cockayne. — Plant Geography of the Waimakariri. 133 



In December, 1898, while on an excursion with Professor 

 K. Goebel, we had an opportunity of observing the vegetation 

 of this region under conditions of dryness, for during the fort- 

 night we were in Westland only a few quite local showers 

 occurred. In the usually extremely moist forest near Grey- 

 mouth the filmy fern Trichomanes reniforme was generally 

 found with its fronds quite withered up and apparently dead. 

 So dry was the subalpine scrub on xVrthur's Pass that some of 

 a sui'vey party with whom we were camped, climbing Mount 

 Eolleston, set fire to a considerable portion. Much of the 

 usually swampy ground was quite dry, and the plants which 

 generally were surrounded by water were growing on ex- 

 tremely dry ground. Outwardly, except as shown by the 

 presence of certain hygrophytes, there appeared nothing to 

 indicate an extremely moist climate. 



From this short account of the climate it may be seen that 

 the plants of this western region have to endure considerable 

 extremes so far as wet and drought are concerned, and with 

 this as one consequence amongst other factors the vegetation 

 is essentially xerophilous. A few hygrophytes and tropo- 

 phytes are also met with, but under exceptional circum- 

 stances. Thus in a climate having an abnormally great rain- 

 fall, and an atmosphere usually charged with much moisture, 

 we meet with plants whose structure seems more suitable for 

 deserts. Such are sclerophytes with tomentose leaves and 

 strong stems {Setiecio viridis) ; herbs with leaves whose in- 

 ternal morphology calls to mind the steppe grasses — Diels, 

 I.e., p. 265 {Gelmisia armstromjii) ; shrubs with much-reduced 

 leaves {Pittosporum rigidum) ; plants whose stems, furnished 

 with coriaceous imbricating leaves, form dense cushions (Do- 

 natia novcB-zclaiidicB) ; tufted plants formed of hard rosettes 

 of incurved, imbricating, needle-shaped leaves, the whole 

 pressed close to the ground {Gelmisia sessilifiora), &c. All 

 the same, the plants as a whole, when compared with those 

 of the eastern climatic region, are not of quite so extreme 

 a xerophilous structure ; nothing is here found to approach 

 in that particular the vegetable-sheep or the coral-broom 

 [Corallospartium) of the eastern ranges. Many plants have 

 considerable leaf -development, and a much greater luxuri- 

 ance of growth generally is apparent. The alpine and sub- 

 alpine meadows are like meadows, and not mere patches 

 of plants surrounded by stony wastes. In the east the 

 subalpine scrub occurs only here and there, but here it forms 

 a great belt at the limit of the upper forest.'*' The never- 

 ending war which is waged for the supremacy between 



* Cockayne, "On the Burning of Subalpine Scrub" (Trans. N.Z. 

 Inst., vol. xxxi., p. 400). 



