Cockayne. — Botanical Visit to the Poor Knights. 353 



(b.) The Tall Scrub Formation. 



Even at a distance it can plainly be seen that much of the sur- 

 face of both islands is occupied by a thick growth of low trees. 

 A closer view shows that some of these stand out distinctly 

 above the others. This at first led me to think that the former 

 might be the iaie Meryta sinclairii, which has for a long time 

 been reputed as occurring on the Poor Knights.* But, as shown 

 further on, these plants are merely Cordyline australis, so that 

 the presence of Meryta on these islands still remains a moot 

 point. 



The formation under consideration occupies the gullies, 

 together with that flatter ground forming the surface of the 

 islands above the precipices. It seems to be of greatest extent 

 on the southern island, where alone I had an opportunity of pene- 

 trating into it. Had the time not been so short it would have 

 been quite easy to have gone right through the scrub to the 

 summit of the island, but as it was I was only able to examine 

 the part at no great distance from the sea. 



Unlike the cliff formation, which is identical with that of 

 the neighbouring mainland, the scrub is quite distinct from 

 any allied formation with which I am acquainted in the New 

 Zealand biological region, not because it contains any peculiar 

 or rare species, but from the special combination of its members. 



Seen from without, the sciub presents a dense mass of foli- 

 age, greyish or green in colour. Between the scrub proper and 

 the open ground bordering on the sea is a broad, thick belt 

 of Phormium tenax, while in places within this again is a good 

 deal of low-growing Metrosideros tomentosa, the representative 

 here of the chaiv.cteristic belt of that tree along most of the rocky 

 shores in northern New Zealand. Here, too, outside the scrub, 

 is Myoporum Icetum — not an erect tree as usual, but semi-pro- 

 strate. This unusual habit did not surprise me, for on the Moko 

 Hinou Islands and on Cuvier I had already observed numerous 

 absolutely prostrate plants, looking on this account altogether 

 different from the normal tree. How far this prostrate habit is 

 hereditary and the plant an elementary species, or whether it is 

 merely a case of fluctuating variation, the result of constant 

 winds on plants which would otherwise be upright, has yet to 

 be ascertained — an easy enough matter to determine by means 

 of culture experiments. 



The two dominant plants of the scrub are Sultonia divari- 

 cata (Myrsinacea?) and Macropiper excelsum (Piper acece). Meli- 

 cytus ramiflorus (Violacece) appears to come next in abundance. 



* See T. Kirk, " An Account of the Puka (Meryta sinclairii, Seem.)," 

 Trans. N.Z. Inst., vol. ii, p. 100, 1870. 



1'2 — Trans. 



