92 Notes on the Flora of Luchnow. [No. 2. 



and at the same time difficult to account for. The want of meteoro- 

 logical observations precludes the possibility of any reason being 

 assigned, and causes us for the present to remain contented with 

 the fact. Dr. Thomson suggests as a possible explanation, a depres- 

 sion in the chain of the Himalaya, north of Luckuow, which would 

 cause a diminished rainfall and consequently a drier climate. Our 

 knowledge of the topography of Nipal is, however, so limited that 

 this suggestion cannot be tested by a reference to maps or altitudes. 



In all parts of India, but especially in the North Western Pro- 

 vinces, there is, as I have already said, a large and diversified non- 

 indigenous Flora. To a young botanist, these plants are most 

 perplexing and it is not for several years that he is able to distin- 

 guish the truly wild species of his district from those that have 

 been introduced. In no book has this character of the Elora of 

 Northern India, received sufficient prominence ; even Dr. Royle, in 

 his Illustrations of Indian Botany, only refers to it incidentally. 

 The descriptive works on botany that exist only serve to increase 

 his confusion, as many of the species are included in these works 

 irom the fact of their being natives of the Himalayan or South 

 Indian forests. It seems therefore desirable to accompany the 

 catalogue of the indigenous species by some notice of the culti- 

 vated and introduced plants, and in so doing, I shall distinguish as 

 much as possible between those species which are cultivated on a 

 large scale ? as field crops, and these found only in gardens, or orchards. 



In all climates, plants cultivated for the use of man have an 

 important influence on the physical aspect of the country. In 

 temperate regions, where cereal grains and other annual species form 

 the crops, there is wanting that luxuriance and diversity of form 

 which are given to the tropical landscape by a cultivation composed 

 of the economic palms, plantains, perennial Euphorbiacese, and tall 

 annual grasses and leguminosse. Northern India, with its widely 

 different season shielding at different periods of the year the products 

 of the temperate, as well as of the torrid zone, presents, in a consi- 

 derable degree, the physical appearance of both. 



The cultivation of Upper India may be divided into three periods 

 corresponding to the seasons of the year. 



First — the season of wheat and vetch cultivation, extending over 



