Cockayne. — Botanical Visit to the Poor Knights. 355 



Those of Myoporum labium measure + 14 - 5 cm. by + 6 - 2 cm., 

 whereas Kirk gives from 2 - 5 cm. to 10 cm. long by 1*3 cm. to 

 3-8 cm. broad.* The leaves of the Melicytus and Geniostoma, 

 too, are considerably above the average. But most surprising 

 of all are the leaves of Suttonia divaricata. These on specimens 

 from the Southern Islands measure 11mm. by 10 mm.,f but 

 those of Poor Knights plants are 33 mm. by 22 mm. ; moreover, 

 they are thin, and not " somewhat coriaceous." 



Such luxuriance of foliage on wind-swept small islands, far 

 out in the open ocean, where the contrary might be expected, 

 is not easy of explanation. There is far more shelter than 

 might be thought at first glance, for usually the formation will 

 only get the wind from one quarter, while the dense growth of 

 the whole also protects the individual members. The air, too 

 — although no statistics are available — may be assumed to.be 

 always highly charged with moisture, and so will check trans- 

 piration and encourage leaf-development. Finally, the volcanic 

 soil of the islands is probably extremely fertile. Mr. T. Kirk 

 long ago called attention to a similar condition of affairs on the 

 lava-field of Rangitoto, the well-known landmark in the Hau- 

 raki Gulf, the richness of whose vegetation in conjunction with 

 the apparent absence of soil and water must strike even the most- 

 careless observer. My above explanation, so far as it goes, 

 adds little to that originally put forth by Kirk. J I must confess, 

 however, that it seems to me at best but a partial solution of 

 this puzzling question. 



(c.) Meadow. 



Regarding this formation I can say little, having only seen 

 it from a distance. Captain Bollons, however, as mentioned 

 above, climbed up to the open gound above the cliffs of the 

 northern island, bringing back for me a few specimens of the 

 meadow vegetation. The ground is in many places carpeted 

 with Mesembrianthemum australe. Everywhere is Phormium 

 tenax, sometimes in large masses, at other times dotted about. 

 Large tussocks of Arundo conspicua here and there all over 

 the meadow give a distinct character to its physiognomy. 

 Roundish bushes, too, of stunted Metrosideros tomentosa are 

 frequent. The meadow is broken into in many places by greater 

 or smaller pieces of scrub, thanks to the shelter afforded by the 

 Phormium. Whether this scrub is similar to that described 

 above I am not in a position to say. Neither can I bring for- 



* " Forest Flora," p. 253. 

 f Lot. tit., p. 251. 



J " Notes on the Botany of Wailieke, Rangitoto, and other Islands 

 in the Hauraki Gulf" (Trans. N.Z. Inst., vol. xi, 1879, pp. 451, 452). 



