SALT-SWAMP. 37 
the unstable ground. ‘The green seed-leaves, with which the little 
plant was also provided while attached to the tree, can manufacture 
food-material ; but this is not all, for they are also fleshy and full 
of nourishment, so the young mangrove can live until the time when, 
provided with foliage, it is in a position to manufacture for itself 
in sufficient quantity the sugary foods it requires from the carbonic 
acid of the atmosphere and water. Surely none need cast contumely 
on such a plant as this! 
Much more common than mangrove salt-swamp, or, as it may 
also be called, “tidal forest’’ or “tidal scrub,” is that plant- 
formation which occurs on the floor of tidal rivers and lagoons 
subject to flooding during the highest tides. The plants concerned 
are usually more or less of the rush form, and, seen from a distance, 
present the appearance of a dark, even surface. Hxtremely ex- 
tensive swamps occur at Havelock (Pelorus Sound), Invercargill, 
and many other places. The Invercargill salt-swamp is now being 
reclaimed and turned with surprising speed into well-grassed dairy- 
land of first-class quality. 
The first plant to settle on the clayey or loamy sandy ground, 
so soon as it is able to support salt-swamp plants, is the three-square 
(Scirpus americanus), which on the wetter ground can at first hold 
its own against the subsequent arrivals, thanks to its far-spreading 
underground stems; but finally the next-comers, the jomted rush 
(Leptocarpus simplex) and the sea-rush (Juncus maritimus var. aus- 
traliensis) exclude the light, and the three-square is exterminated. 
In many salt-swamps either the Leptocarpus or the Juncus are 
dominant, but only as far south as Timaru and Okarito; farther 
south the sea-rush does not go, and Leptocarpus reigns alone. 
There are also other members of the formation—e.g., the sea- 
sedge (Carex litorosa), which is found only in salt-swamp ; the swamp 
twig-rush (Cladiwm junceum), but this only in the north of the North 
Island, though the species extends to Foveaux Strait ; the succulent 
Australian glasswort (Salicornia australis); the slender New Zealand 
celery (Apium filiforme); and the shore-cotula (Cotula dioica) form- 
ing green mats, the leaves highly aromatic when bruised. In deep 
pools is the grass-like sea club-rush (Scirpus robustus), a summer- 
green grass-like sedge; and on the driest ground a black ball-like 
divaricating shrub of more or less deciduous habit, the shrubby 
ribbonwood (Plagianthus divaricatus), takes complete possession. 
