70 ORDERS. 



CLASS 15. Tetradynamia. 



This, like the last, has but one pistil* It has two or- 

 ders, hoth very natural, and distinguished by the form 

 of the fruit. 



1. SILICULOSA, fruit a silicle fsiliculaj or roundish 

 pod. Ex. Shepherd's purse, Thlaspi, 



2. SLLIQUOSA, fruit a silique fsiiiquaj or long pod. 

 Ex. Stock-July, Cabbage, Mustard. 



The orders of the 16th, 17th and 18th classes, Man- 

 adelphia, Diadel^Jna and Polyadelpkia, are founded on 

 the number of the stamens, that is, on the characters of 

 the thirteen first classes, and have the same names* 

 TRIANBRIA, PENTANDIUA^ &c. 



Observation. It may appear inconsistent to the student, that 

 there should be orders Triandria &c. when there are classes of the 

 same name ; but he will observe, that these are orders of classes, 

 which have their character not from the number of stamens, but 

 from some other circumstance ; in the classes above, from the 

 union of the filaments, the number of the stamens being unappropri- 

 ated is taken to characterize their orders. 



CLASS 19. Syngenesia. 



Observation The orders of this great natural class are frequently 

 complained of, as being difficult to be understood It is true there 

 are a number of particulars relating to compound flowers, which 

 should be attended to by the student, before he can possibly have 

 a clear conception of these orders. Each of these particulars is 

 easy enough in itself; and it is only for want of attention to them 

 that he meets with any difficulty in understanding the orders. 



As the class is a very extensive and interesting one, the student 

 is directed to attend to the points alluded to above, in the follow- 

 ing 



Analysis of Compound Flowers. 



1. A COMPOUND FLOWER* is formed by the union of seve- 

 eral fructifications or lesser flowers, called florets, placed together 

 upon a common receptacle, and enclosed in a common calyx ; each 

 floret being furnished with fivti stamens, distinct at bottom, but 

 united at top by their anthers into a tube or cylinder, through which 

 passes a style considerably longer than the stamens, and crowned 

 by a stigma or summit with two divisions, that are generally rolled 

 backward like a recurved fork. 



2. Each floret has a monopetalous corolla. 



* The Class Syngenesit is made up of compound flowers, 



