Mr Don on the Characters of the Class Personates. 109 



by their curved embryo; and the CestrinecB by their valvate 

 aestivation and regular flowers. As neither of the groups above 

 mentioned conveys an adequate idea of the order, I could have 

 wished, therefore, that the name of Personatee had been retained 

 for it instead of that of Scropliularmcce, especially as Scrophu- 

 laria is to be regarded as an aberrant genus. 



RHINANTHACE^. 



This family, consisting of Rhinanthus, Pedicularis, Melam- 

 pyrum^ and Cymbaria, is intimately allied to the precedino- or- 

 der, but limited as here proposed, it is satisfactorily distinguish- 

 ed by its inverted embryo, with the radicle directed to the op- 

 posite extremity of the seed. The EiiphrasiecB have been in- 

 cluded by most botanists in this family, and were they to be re- 

 tained, the separation between it and the preceding order would 

 be rendered impossible. Cymbaria differs from the rest of the 

 order in the very considerable degree of development of its 

 embryo. 



OROBANCHE^. 



A very natural family, well distinguished from the precedino- 

 by their persistent corolla, unilocular ovarium, centrifugal em- 

 bryo, and peculiar economy, in being for the most part parasi- 

 tical herbs, destitute of proper leaves, and of the green colour 

 common to other plants. The seeds are attached to the narrow 

 depressed placentae, formed by the united edges of the valves. 

 The embryo is placed in the ventral side of the seed, and at the 

 opposite extremity from the hilum, resembling a minute nearly 

 globular homogeneous mass, and, as far as I have been able to 

 observe, perfectly undivided, and consequently devoid of true 

 cotyledons. In all these respects Obolaria and Tozzia seem to 

 agree, but differ in having proper leaves, and in being terres- 

 trial. 



CHELONE^. 



This group is well entitled, in my opinion, to be retained apart 

 from the Scrophularinece, on account of the greater degree of 

 development of its embryo, its compressed winged seeds, and of 

 the presence of a rudimentary stamen, all of which characters 

 bring it near to the PeduUnece and Bignoniacece, from which it 

 is distinguished by its albuminous seeds. 



ARAGOACEjE. 



The single genus constituting this group, is one of the most 



remarkable in point of structure in the whole class. Its regular 



symmetrical flowers, the twisted aestivation of its corolla, and 



the structure of its seeds, bring it very near to the Polemonia- 



