FLORA OF THE NICOBAR ISLANDS. 5 
with such dense and impenetrable underwood, as 1 found here on the 
southern Nicobars. At the neighbouring Pulo Penang, for instance, 
neither are the still remaining forests so grand, nor the ‘underwood so 
crowded, as to prevent their being traversed with small difficulty. 
As I have said already, the dense part of the forests, in which under- 
wood is mostly wanting, is peculiar to the southern islands ; while the 
more open portion, which is furnished with underwood, is much 
narrower on the northern islands, with the exception perhaps of Car- 
Nicobar,—its outer margin imperceptibly dwindling into the vegetation 
of the more recent alluvium. It is frequently extended, towards the 
interior, into low valleys, without being met there with any dense 
forests. On the contrary, the forest becomes more open and low, and 
is gradually succeeded by a number of elegant shrubs, chiefly of the 
genera Irora, Inga, Cassia, Colubrina, Flemingia, Bauhinia, Vitex, 
Mesa, Erycibe, Leea, Rubus (moluccanus), Mussenda (frondosa), and 
Melastoma (Malabathricum), mixed with shrubby or arborescent ferns. 
Heath-like tracts covered with a sort of fern (Gleichenia), or luxuriant 
grass-plains, occasionally take the place of those shrubs. Within the 
belt thus formed, the hills are on the whole covered with grass only. 
The sod towards the inner confines of the forest, at places where the 
soil is richer and more moist, is formed of soft, juicy grasses, and in 
part of stiff and arid sorts of Cyperacee (Scleria, Cyperus, Diplacrum) ; 
but the greater area is occupied by more delicate, yet dry and stiff, 
grasses, among which a species of Imperata (Lalang) performs an 
important part. This is almost the only plant on the Nicobars which, 
being in the highest degree social, occupies whole tracts of land, ex- 
cluding all other lower vegetation, and admitting only here and there, 
on the borders, the growth of other sorts of grasses, and of some 
species of Alysicarpus, Desmodium, Uraria, Smithia, and Crotalaria, 
which may be compared in some degree with our clovers. Towards the - 
top of the hills even the grasses become scanty and stinted, ceasing at 
length altogether on spots where the clay is covered by a coarse sand, —— 
containing some iron, and washed into barrenness by the frequent falls —— 
of rain, and producing only few and poor plants of species of Zewcas, - 
Aerva, and Evolvulus. Although all these grass-plains possessed some _ 
degree of freshness, yet they exhibited such a uniformly arid, barren, - 
steppe-resembling picture, as to have nothing like it in our country. z 
ge — from the difference in the soil, produce — 
