166 Podostemacea. 



same species and another, were found by the late Mr. 

 Griffith in Assam, and their description forms part of a 

 valuable paper which he published in the 19th Vol. of the 

 ■ Asiatic Researches.'* Since that period no new species 

 have been published, belonging to the Indian Flora. 



In the early part of last year (1845), having been sent by 

 the Government of Ceylon to visit Dr. Wight at Coimbatore, 

 on matters connected with the Botany of the Island, we 

 spent the month of February together on the Neilgherry 

 mountains, where we made very large collections. Among 

 many other plants, we found no less than three species of 

 Podostemon, on rocks in rapids in the bed of the Pycarrah 

 river. These, together with another which I possess from 

 Dr. Wight, found by him the year before in the same 

 stream, and three species which I have lately discovered in 

 Ceylon, as well as a species of Tristicha, which I have also 

 lately added to the Flora of the Island, I purpose to give de- 

 tailed descriptions of in this article. Before doing so, how- 

 ever, I shall make a few observations on the habit and struc- 

 ture of the plants which comprise the natural order, on the 

 characters of the genera, and on the relations which the or- 

 der bears to other tribes. 



The whole of the plants belonging to the order are truly 

 aquatic in their habits ; and it is but seldom that they are 

 found in still water, the most of them growing on rocks and 

 stones in rapids and water-falls. Most of them are annuals, 

 at least all those which I have met with, either in the New or 

 the Old World are so, and are only found in flower in the 

 dry season, when the water in the streams is very much dimi- 

 nished. They only come into flower just as the water is 



* It is not very creditable to our literary taste in Ceylon, that there does 

 not exist either in the Public Libraries of Colombo or Kandy, a complete set 

 of the • Asiatic Researches,' although it is a work which bears so intimately on 

 the History, Religion, Antiquities, Languages, and Natural History of the Island. 

 For the use of the part containing Griffith's paper, I am indebted to the kindness 

 of Dr. Wight, having been obliged to send to India for it. 



