328 CORALS AND CORAL ISLANDS. 
character. It grows sometimes to a height of thirty feet. It 
is well fitted for the poor and shallow soil of a coral island ; 
for, as it enlarges and spreads its branches, one prop after 
another grows out from the trunk and plants itself in the 
ground ; and by this means its base is widened and the grow- 
ing tree supported. The fruit, a large ovoidal mass made up 
of oblong dry seed diverging from a centre, each near two 
cubic inches in size, affords a sweetish husky article of food, 
which, though little better than prepared corn stalks, admits 
of being stored away for use when other things fail; and at 
the Gilbert Islands and others in that part of the ocean it is 
so employed. 
The Pisonia is another of the forest trees, and one of 
handsome foliage and large beautiful flowers, sometimes 
attaining a height of forty feet, and the trunk a girt of 
twenty feet. | 
Among the species that are earliest in taking root in the 
emerging coral debris over the reef, there are the Portulacee 
(species of purslane); the Zriwmphetta procumbens, a creep- 
ing, yellow-flowering plant of the Tilia family; the Tourne- 
fortia sericea, a low, hoary shrub of the family Borraginacee, 
and Scevola Konigii, a sub-fleshy seashore plant. 
On Rose Island, just east of the Navigator Group, Dr. C. 
Pickering, of the Wilkes Exploring Expedition, found only a 
species of Pisonia and of Portulaca. This is a small atoll, 
under water at high-tide, excepting two banks, one of which 
is covered with trees. 
In the Marshall Group, on the contrary, where the vege- 
tation is more varied, and the islands have probably under- 
gone some elevation since they were made, Chamisso observed 
fifty-two species of land plants, and in a few instances the 
banana, taro, and bread-fruit were cultivated. At the ele- 
