152 CONTRIBUTIONS TO 



and one that will probably be found to constitute an unerring 

 line of distinction between the Solanacece and Scrophu- 

 larinea, orders so closely allied, that our most able 

 Botanists are yet often undecided as to which of the two, 

 certain plants ought to be referred. This is a desideratum 

 of some moment, and one that appears to me worthy 

 of being pursued : it seems to me possible to reconcile 

 all the discrepancies that at first view stand in the way 

 of such a line of demarcation : indeed, there exist many 

 singular analogies between some plants of the Salpifflossidea, 

 and other Scrophularineous genera, and some of tribes of 

 the Solanaceee as above defined, which will probably assist 

 us in this inquiry, but I will reserve to a future opportunity 

 the exposition of my sentiments on this subject, in order 

 to have more ample means of examining the characters of 

 these plants, and of availing myself of the assistance that 

 will be afforded by the extensive views, and vast collection of 

 facts, made by the learned author of the monograph of 

 the Scrophularinea, in the forthcoming volume of the Pro- 

 dromus, 



Sessea. 



In order to confirm what I have before stated respecting 

 the affinities of Metternichia, I will offer a few observations 

 upon the genus Sessea of Ruiz and Pavon, two species 

 of which are only recorded, both being well figured by 

 the authors of the Flora Peruviana; but as I have also 

 had an opportunity of examining two other undescribed 

 species existing in the splendid herbarium of Sir William 

 Hooker, and as the characters of the seed have not been 

 yet sufficiently well determined, I venture to propose here 

 an amended definition of the genus and a description of 

 the four species. 



Sessea, R.&P. (Char, emend.)— Calyx tubulosus, 5-den- 

 tatus. Corolla hypogyna, infundibuliformi-tubulosa, limbi 

 5-fidi erecto-patenti laciniis ovatis, cestivatione condu- 

 plicatis. Stamina 5, tubi medio corollce inserta, inclusa ; 



