I.—INTRODUCTION. 13 
land abuts so closely on wayside and watercourse as to leave no 
foothold for those species that form the roadside hedges and fill the 
weedy waste places so characteristic of Lower Bengal. Even the 
“171 1 25 s 41 L Pho wees 1 fe £ ¢ i 1, At aw 
area, are in Tirhut conspicuous by their absence. The result is that, 
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except for the water-pia. Ze ; 
the vegetation of Tirhut is chiefly limited to the crops with their 
concomitant field-weeds; even the latter are often conspicuous by 
their paucity. To this state of affairs is largely due the fact that 
our collections from South Tirhut are few and scanty. Of North 
Tirhut, where our province abuts on the submontane forest, here 
mostly within the Nepalese frontier, we know very little, the only 
collections of importance from the region being those of Buchanan- 
Hamilton, few of whose specimens are in India now, and more 
recently those of Hieronymus, the latter being altogether from 
Bettiah, the extreme north-west district of Tirhut. It is to be 
expected that, if carefully looked for, many of the plants charac- 
teristic of Gorakhpur, beyond the Gandak to the west, may yet be 
found in Tirhut. Behar, too, requires systematic re-exploration, 
for, though there are many Behar plants in the collections of 
milton, Wallich, and Hooker, and especially in those of Kurz, 
much probably still remains to be collected. Chota Nagpur has 
received closer attention than Tirhut and Behar, large and valuable 
collections having been made there by Hooker, Thomson, Anderson, 
urz, Clarke, Gamble, and, especially, by Wood, Campbell, and 
aines. But our knowledge of the Chota Nagpur flora is still far 
from adequate; much has yet to be done, particularly in the 
southern and south-western parts of the province. 
Unlike the other western provinces, Orissa, in place of being a 
compact natural area, is an exceedingly composite one. The inner 
highlands form, like those of Chota Nagpur, a plateau with oc- 
easional higher hills, some of which actually reach subtemperate 
altitudes. The ghats that lead up to these highlands are con- 
tinuous to the north with the eastern escarpments of Chota Nagpur, 
to the south with the Eastern Ghats—those “ mountains of the 
Cirears,”’ from which, more than a century ago, Roxbargh obtained 
so many plants, of which he has left excellent drawings, that no one 
as seen since. The submontane strip below is continuous to the 
north with the drier part of West Bengal, which has a vegetation in 
