46 THE CLASS DIANDRIA. 



CHAPTER XI. 



OF THE CLASS DIANDRIA. 



In studying the plants of this and some other 

 classes, great facility will be derived from attending 

 to the divisions under which the genera are arranged 

 in all the systematic books. 



In this class, though not numerous, we shall not 

 find so great a difficulty in obtaining specimens for 

 examination as in the preceding. There are few 

 gardens which do not contain the Ldlac and Privet. 

 They are both provided with an inferior, tubular 

 corolla ; with a quadrifid or four-cleft border ; but 

 they are distinguished from each other, as genera, by 

 the diiFerence of their fruit ; that of the Privet (Li- 

 gustrum) being a berry with four seeds ; that of the 

 Lilac (Syringa), a flat and dry capsule of two cells, 

 with many seeds. The species of Lilac may be 

 known apart by the leaves, as, in the common Lilac, 

 where they are heart-shaped ; and in the Persian 

 (Syringa persica), where they are narrow and lance- 

 olate or lance-shaped ; of this last, there is also a 

 variety with the leaves pinnatifid or cleft on either 

 side into parallel segments, after the manner of the 

 divisions of a feather. That it is only a variety is 

 proved, by its seeds producing plants of the ordinary 

 kind, as also takes place in the Parsley-leaved Elder, 

 a mere variety of the common species. 



In wastes, by road-sides, where there is a little 

 moisture, in ditches, and in neglected gardens, you 

 will find early in the spring, and late in autumn, a 

 set of very humble plants, mostly introduced by acci- 

 dent from Europe, forming another common genus of 

 plants belonging to this class, called in Europe, Speed- 



