OF REJECTING CERTAIN GENERA. tm 



for in full flowers no number of petals can be assigned, and the 

 stamina are generally wanting, the number of which makes a 

 part of the generic character ; and in mutilate flowed, as in 

 some species of Campanula, Ipom^ea, and Ruellia, the corolla 

 would be excluded from the description, contrary to the nature 

 of the other species of the genus. But as the calyx*, in full 

 flowers, is scarce ever altered, it may detect the genus; and the 

 lowest series of petals in polypetalous corollse remaining the 

 same in respect to number, the genus may also be often known 

 by that character; as in Papaver, Nigella, and Rosa, 



CHAP. XXXI. 



Of the Genera rejected by the Sexual System, as not 

 established on the Fructification. 



WE have observed, in Chap. XXIX. that the earlier botanists 

 had admitted many genera, on distinctions that were not ground- 

 ed on the parts of fructification, but on the habit of plants, and 

 on other circumstances, which are now considered as specific di- 

 stinctions only : of these we shall here give an ample list. The 



* Some systematists have distributed the whole body of vegetables by the differ- 

 ences of the calyx; and in such systems the full flowers, as our author observes, 

 are more easily referred to their proper genus than in his own, the calyx not being 

 subject to luxuriancy. Instances of this are in hepaiica, ranunculus, and alcea,. 



Author. 



We frequently find the calyx also luxuriant, and the lower leaves of the corolla in- 

 creased in number. Luxuriant plants are easily known, when the single are well un- 

 derstood, primd facie, and the young student would do well at first to pass these 

 ever. Eoitok, 



