148 CLASS D1ADELPHIA. 



New Holland, which, possessing separate filaments, 

 are forcibly, as we may say, detained in the simple 

 tenth class. Nor are exceptions wanting in other 

 parts of this artificial class, for in Corydalis cucullaria 

 there are G distinct filaments. In very few of the 

 genera is there any thing like an equal proportion in 

 the 2 bodies of filaments. In the whole order of the 

 Lecuminos-k, there are only about 3 examples of the 

 stamina arranged in equal sets of 5 each ; these are 

 the genera Smithia, Sesbania, and JEschynomene. In 

 all the rest of this great natural order, the stamina 

 are either wholly combined into one body or cylinder 

 of ingrafted filaments, or with but one thread sepa- 

 rated from the other 9, which are combined in the 

 second body. 



The orders, as in Monadelphia, are founded on 

 the number of the stamina, the classical or principal 

 arrangement having regard only to the peculiar and 

 remarkable disposition, of the binary ingraftment of 

 the staminiferous filaments. The only orders yet 

 discovered are 4 ; namely, Pentandria, Hexandria, 

 Octandria, and Decandria. 



The only plant comprised in the first of these 

 orders, Pentandria, is a very curious and highly orna- 

 mental genus, peculiar to the prairies or savannahs oi 

 the western and southern states and territories of the 

 United States, formerly included in Dalea, but very 

 properly separated by Michaux, and now known as 

 Petalostemon, expressive of its most remarkable trait, 

 that of producing its petals, 5 in number, and uni- 

 form, from the same tube of combined filaments, 

 whose other threads produce anthers. Indeed, no 

 other petals are produced but these, which thus hold 

 the place of sterile anthers. The 5-cleft calyx, which, 

 like Clover, nearly covers the very small, 1-seeded 

 legume, is characteristic also of Dalea ; but in Dalea 



