682 Mr. Bentham's Account of two new Genera allied to Olacinese. 



have thought it more convenient to keep them together under the general 

 character above given. Those species of Olax in which the dissepiments of 

 the ovary are almost obliterated form the connexion with Opiliece, and, as far 

 as known to me, Gomphandra appears to join OpiUece with Icacineœ, whilst 

 Pogopetalum is in many respects equally allied to Olaceœ and Icacineœ. 



The first tribe, where the double nature of the floral envelopes is most evi- 

 dent and complete, is that which comes nearest to the various polypetalous 

 orders, with which Olacineœ have been compared. But among these, I can- 

 not admit the affinity to Aurantiacece. The structure of the seed, where 

 it is so constantly and materially different as in these two orders, becomes 

 one of the most important characters in the classification of Dicotyledons ; 

 and it is here accompanied by considerable differences in the fruit, in the 

 ovary, in the eestivation of the corolla, in the texture of the vegetable organs, 

 and otlier points of liabit. And those peculiarities, in wliich Aurantiacece 

 appear to resemble Olacineœ, such as the tendency of the petals to cohere by 

 means of the stamens, the persistent calyx, &c., occur in other orders which 

 are less removed by essential characters. 



MeliacecE, nearly aUied to Aurantiaceœ, are about equally distant from 

 Olacineœ in essential characters, and more so in habit. 



Humiriaceœ, a small order usually associated with Meliaceœ and Aurantia- 

 ceœ, differ from them in habit, in the ovary, the fruit and the seed ; in all of 

 which points they approach much to Olacineœ. The dissepiments of the ovary 

 are, when young, not quite complete, and the embryo lies in the axis of a 

 copious albumen. They differ chiefly from Olacineœ in the aestivation of the 

 corolla, which is not so decidedly valvate, in the stamens often indefinite in 

 number, in the dilatations of the connectivum of the anther, the presence of a 

 disc round the ovary, the fruit more generally plurilocular, and the larger 

 embryo with a long radicle ; but, upon the whole, they are probably, among 

 dichlamydeous plants, those which come nearest to Olacineœ. 



Styraceœ*, which are perhaps more allied to polypetalous orders than to 

 those which are essentially gamopetalous, are very near also to Humiriaceœ as 

 well as to Olacineœ. The structure of the fruit and seeds may indeed be 

 compared to those of Scltœjifia, that of the ovary in some respects to Pogope- 



* Including Symploceœ and Halesiacea of Don. \'id. Trans, Linn. Soc. Lond., vol. xviii. p. 230. 



