1 66 
THE VEGETATION OF THE DISTRICTS OF 
Over 6o per cent, of the species in this list, which is largely 
composed of plants introduced for economic reasons, have already 
become so completely naturalised as to form an integral portion of 
the wild vegetation of our districts In some cases it will be s^en 
the species have become so familiar to the inhabitants that they 
have received distinct vernacular names ; some of them, indeed, like 
the Agave , one species at least of which was introduced over three 
hundred years ag:>, and like Thevetia , which was introduced a century 
ago, enjoy in otner parts of India, if not in our districts, the distinc- 
tion and dignity of having had Sanscrit names evolved to designate 
them ! 
But if the extent to which woody species that are natives of the 
New World have acclimatised them?elves in Lower Bengal is very 
striking, still more striking is the extent to which herbaceous species 
have accommodated themselves to our deltaic conditions. The 
' following list of American plants that are very familiar in the Calcutta 
neighbourhood shows that out of 50 species, 80 per cent, have become 
quite naturalised * Talinum paens, * Crotalaria Brownei and 
*C,incana, * Phiseolus s j m>erectus, * Cassia alata y * Neptunia 
plena , *Turnera ulmifolia y * P assiflora suberosa and * P . fcetida y 
Eupatorium Ayapana and E. odoratum ) * H ymenantherum tenui - 
folium, * Tage f es patula and T. erect a, * Zinnia pauciflora , Tithonia 
tagetiflora — this species is not self-sown but propagates itself by its 
roststocks, Helianthus annuus and * H. argyrophyllus , * Cosmos sul - 
fu reus , * Vinca rosea,* Asclepias Curassavica , * Phlox Drummondi 
— only occasionally self-sown, * Merremia umbellata , Ipomoea purpu- 
rea and /. tricolor , * Quamoclit phoenicea and Q. pinnata i * Solanum 
glaucum and * S. sisymbriifoliu m, Physalis peruviana , * Petunia 
nyctaginiflora — only occasionally, * Browallia elata } * Martynia 
diandra , * Ruellia tuberosa , * Stachytarpheta indica , * Hyptis capi - 
tata — only occasionally, * Salvia coccinea , *Mirabilis Jalap a ) * Gom~ 
phrena globosa * Rivina humilis , Euphorbia pu:cherrima ) * E. geni - 
culata — only occasionally, and * E. heterophylla, * Ananassa saliva , 
* Ciput a paludosa, * Zephyranthes tubispatha — occasionally, Polian - 
thes tuberosa , * Tradescantia discolor — occasionally, * Pteris cretica. 
In addition, however, to these intentionally introduced species 
there are a considerable number of inadvertently introduced plants 
in our districts. To what extent the species in our districts which 
are undoubtedly natives of Northern or Western Bengal belong to 
this category is a matter that hardly repays speculation. Some 
there certainly are, such as Andropogon contortus , Saponaria 
Vaccaria ) Cardamine debilis , Lathy r us Aphaca , Melilotus alba y that 
