Cockayne. — Botanical Visit to the Poor Knights. 357 



an island, is a case in point. Here Cfteeseman* discovered four 

 plants not found elsewhere, which may well be considered 

 either remnants of a more extensive ancient coastal flora, or 

 new species which originated during a separation of the place in 

 question from the mainland. But in the case of Carmichcelia 

 williamsii the former supposition seems the more feasible. This 

 view is also supported by the occurrence of Veronica macroura 

 on the Poor Knights, another species known authentically only 

 from the East Cape region and the coast for some distance to 

 the south, including Portland Island. 



3. Summary of Results. 



1. There are three principal plant formations on the Poor 

 Knights — viz., cliff, tall scrub, and meadow — and a minor forma- 

 tion composed principally of halophytes. 



2. The cliff formation is identical with that of the adjacent 

 coast. 



3. The scrub, owing to the combination of its members and 

 the presence of Suttonia divaricata as a dominant species, differs 

 from any allied formation in the New Zealand biological region. 



4. Carmichcelia williamsii, a plant hitherto only known from 

 the East Cape district, much further to the south, occurs on the 

 Poor Knights, and its limited distribution in New Zealand may 

 be explained on the supposition of a shrinkage of the land-surface, 

 with a consequent increase in the struggle for existence and the 

 extinction of plants over wide areas, leaving the survivors iso- 

 lated in such places as small islands. 



5. The arborescent plants exhibit a most remarkable lux- 

 uriance of foliage, greater considerably than that of the same 

 species on the mainland. 



Before concluding I must express my sincere thanks to the 

 Hon. W. Hall-Jones, Minister of Marine, for his kind assistance 

 in furthering my botanical work on this and previous occasions. 



4. List op Plants collected or observed on the Poor 



Knights. 



Filices. 

 Asplenium flaccidum, Forst., var. 

 Polypodium serpens, Forst. 

 Pteris esculenta, Forst. 

 tremula, Br. 



»> 



* " On the Flora of the North Cape District" (Trans. N.Z. Inst,, vol 

 xxix, 1897, p. 363). 



