MR. G. BENTHAM ON EUPHORBIAOE^l. 199 



III. SYSTEMATIC ARKANGEMENT. 



The general affinities of the Order have been repeatedly dis- 

 cussed. Euphorbiaceae have been severally compared with Malva- 

 ceae, Sterculiaceae (especially Buettnerieae), Rutaceae, Rhamneae, 

 Celastrineae, Chailletiaceae, and even Menispermeae, among Poly- 

 petalae, and with Urticeae and a few others among Monochiamy- 

 dere. But though there are individual genera which may exhibit 

 some one character supposed to be nearly peculiar to some of 

 those orders, yet no real connexion has as yet been pointed out. 

 The isolation to which 1 shall further on have occasion to allude, 

 is produced not so much by any one special character as by a 

 special combination of several. And if a few genera may have 

 been bandied about between Euphorbiaceae and other orders on 

 account of the supposed identity of some one of these characters, 

 it will be found to be owing to their having been imperfectly 

 known from specimens of one sex only, or otherwise defective, so 

 as not to show how that character was connected with all others. 



But if it be admitted that Euphorbiaceae constitute an isolated 

 group, nearly equally surrounded by several others, there remains 

 the question (which it is necessary to decide) Where should they 

 be placed in the linear series which, though not in Nature, we 

 are compelled to adopt ? In the Candollean arrangement (which, 

 with all its defects, we have followed in our ' Genera Plantarum ' 

 for want of a better one) they come under Monochlamydeae. As, 

 however, a considerable number of the genera have petals, they 

 have supplied one of the principal grounds for the often proposed 

 breaking up of the class of Monochlamydeae and distributing their 

 orders amongst Polypetalae ; but even then the most eminent of 

 the botanists who have attempted to do so are not at all agreed 

 as to where Euphorbiaceae should be placed in that class. Some 

 would bring them near to Rhamneae and Celastrineae, to which 

 many Phyllantheae and Galearieae indicate an approach ; others 

 rely upon the petaliferous Crotoneae as showing an affinity with 

 the Malval alliance. In either case their practical insertion 

 among Polypetalae has generally been between orders more 

 nearly allied to each other than to Euphorbiaceae ; and many of 

 the petalless Crotoneae, especially Hippomaneae, appear to me to 

 show quite as near an approach to Urticeae as do the Phyllantheae 

 to Rhamneae. As, therefore, the order cannot be broken up, its 

 old place among Monochlamydeae seems to be the best suited to 



