D1ADELPH1A. J 79 



CLASS XVIL DIADELPHIA. Stamens united in tun 

 parcels. Orders 4. 



The name of this class comes from dis, Fi - R - 



twice, and adelphos, a brother, and is usu- 

 ally called two brotherhoods, in allusion to 

 the union of the stamens into two distinct 

 partis. Provided the stamens are in two 

 sets it is not essential with respect to num- 

 bers how the division is made. In some 

 instances the stamens are equally divided, 

 and in others there is a single one in one 

 set, and a half dozen or more in the other ; the two parcels 

 are often united at the base. The orders are distinguished 

 by the number of their stamens. The flowers of this class 

 are almost universally papilionaceous, or butterfly shaped. 



With respect to this class as applicable to the useful pur- 

 poses of man, it bears the very highest rank. All the vari- 

 eties of beans, peas, vetches and lentils are Diadelphous 

 plants, and many of the best grasses, as well as a variety of 

 useful and ornamental trees, belong here. The genera are 

 very unequaJy divided with respect to the orders, nearly 

 nine tenths of the whole class having ten stamens, and 

 therefore falling under the order Decandria. 



ORDER I. PENTANDRIA. Stamens 5. 

 This order contains only two genera, and these are with- 

 out use or interest. 



ORDER II. HEXANDRIA. Stamens 6. 

 UENUS Fumaria. Fumitory. Name from fumus, smoke, 

 in allusion to the disagreeable smell of the plant. Fumaria 

 officinalis was formerly used in medicine. The species are 

 chiefly handsome weeds. 



ORDER III. OCTANDRIA. Stamens 8. 

 GENUS Polygala. Milk-wort. Name from the Greek 

 polu, much, and gala, milk, because some of the species 

 were anciently supposed to excite the lactescent secretions. 

 The only species worthy of notice is the Rattlesnake root, 

 (Polygala senega,} which is employed in medicine in cases 

 ot asthma and catarrh. It is said also that the Indians em- 

 ployed this root as an antidote against the bite of the rattle- 

 How are plants of the class Diadelphia characterized ? How are the 

 orders of this class distinguished ? What rank do the plants of thjs class 

 bear, as applicable to the wants of man? 



