Hourroyn anp Kirx.—Description of Arid Island. 111 
of its flora approximated closely to that of the Little Barrier Island, which 
it so nearly resembles geologically. A complete examination of Arid Island 
and the Little Barrier would probably result in the discovery of other plants 
common to both but absent from the Great Barrier besides those observed 
by us. 
The flora of the island may be roughly divided into Ericetal, or plants 
of the open land; Sylvestral, or forest plants; Littoral, or beach plants ; 
and Uliginal, or marsh and swamp plants. It need scarcely be remarked 
that these terms are not always capable of precise application. 
The greater portion of the central area of the crater and its rim is 
occupied by Ericetal plants; in the lower parts, a dense growth of Pteris 
esculenta, which often attains the height of six feet, intermixed with occa- 
sional tufts of Phormium tenax, renders all progress slow and laborious. On 
higher parts and in open places the fern is supplanted by Leptospermum 
scoparium and Pomaderris phylicifolia, sparingly intermixed with bushes of 
Coprosma robusta, C. lucida, Carmichelia australis, Leucopogon fasciculatus, 
Veronica salicifolia, Coriaria ruscifolia, and other small shrubs. Agrostis 
emula, Leucopogon frazeri, Drosera auriculata, Lobelia anceps, Haloragis 
micrantha, Lagenophora forsteri, &c., &c., were common amongst open fern, 
together with the ubiquitous introduced plant Erigeron canadensis. 
pretty Ophioglossum lusitanicum was seen on tufaceous ledges, and was after- 
wards observed in exactly similar habitats on the Little Barrier, but appeared 
to be entirely absent from the Great Barrier. Many specimens had two or 
more scapes springing from the same root, a peculiarity it shares with other 
forms of the genus in New Zealand, although all the forms collected in the 
northern hemisphere have invariably solitary scapes. On the highest points 
of the island, as in fact of all islands and headlands in the north of New 
Zealand, Astelia banksii and Metrosideros tomentosa were invariably found. 
Astelia banksii, we may remark, is always rupestral in its habitat, never 
epiphytal ; nor is it found at any great distance from the sea, so far as 
our experience extends. From personal observation, we can testify it is 
abundant on rocks at Mercury Bay, where we sought for it in vain “on 
the limbs of trees," as reported in the * Handbook of the N. Z. Flora." 
Astelia cunninghamii is both epiphytic and rupestral, and is most frequently 
found inland. 
The sheltered open spaces at the base of the cliffs on the exterior of the 
crater, and large portions of the northern and southern sides of the interior, 
are occupied by the Sylvestral portion of the flora in the crater itself, 
forming a somewhat open bush, although few of the trees attain large 
dimensions. As might be expected, the Pohutukawa (Metrosideros tomentosa), 
is abundant, although greatly inferior in size and appearance to the fine 
