COASTAL-ROCK ASSOCIATIONS. 39 
green colonies of the shore-dock (Rumex neglectus) ; the tiny creamy- 
white stars of the dwarf bedstraw (Asperula perpusilla) are every- 
where; red mats of the shore-stonecrop (Crassula moschata) occur 
abundantly ; and in the wet pools is the water-chickweed (Montia 
fontana). 
The varied coast-line, combined with the mountainous character 
of portions of the coast, to say nothing of the geological structure 
of the rocks, has led to a considerable variety of coastal-rock associa- 
tions, as well as to a rich rock-flora. About 100 species, belonging 
to 37 families, are more or less common on coastal rocks, but only 
about 30 species are found where there is much sea-spray, and 
there is not one which is confined to pure rock alone. 
The ice-plant (Mesembryanthemum) association is truly coastal ; 
it occurs in all parts of New Zealand proper. The plant itself 
(M. australe) frequently forms green masses hanging downwards on 
the cliff-face so that they can be raised like a curtain. There may 
be little else than the ice-plant, but generally the succulent Aus- 
tralian glasswort (Salicornia australis)—this the first-comer on rocks 
just left bare by the sea—the wild celery (Apiwm prostratum), and 
the shore-groundsel (Senecio lautus) are present. When less exposed 
to spray, in the North Island, there is the taupata (Coprosma 
retusa), \ts extraordinarily thick, fleshy, polished leaves closely rolled, 
and the plant itself hugging the rock. In the north of the North 
Island and the Marlborough Sounds the rock-lily (Arthropodium 
curratum), called in the latter locality the ‘‘ Mabel Island lily,’ its 
broad green leaves 2 feet in length, forms pure colonies. The shore- 
spleenwort (Asplenium obtusatum) is sometimes a member of this 
association. Less spray, and many other plants invade the rock, 
some of them common lowland shrubs—e.g., the manuka (Lepto- 
spermum scoparium). 
One rock association is dominated by a tree, the pohutukawa 
or Christmas tree (Metrosideros tomentosa), of which the Aucklanders 
are so justly proud. It was formerly much more abundant than 
at present. It grows frequently on the faces of clifls, stretching 
outwards over the oyster-covered rocky shore. Some of its roots 
are fixed in the solid rock, and creep for long distances over the 
surface—a most remarkable sight—while others are given off quite 
high up the trunk or from the branches; but these do not usually 
reach the ground. Not infrequently the pohutukawa is of a quite 
