r" 



i 



3XK. BENXIIAM ON LOGAXIACE^. 



OO 



( 



! 



1 



the country, it may be more convenient to draw the line close 

 round the frontiers of the whole space, than to portion it out into 

 projecting parcels annexed to the adjoining woods. 



On a careful examination, it will be found that almost the whole 

 oi the Loganiacecd lie very near to some part or other of the vast 

 field of Ruhiacece^ although by their free ovary they are absolutely 

 and with very few exceptions clearly separated. The connecting 

 genera with Apocynece^ Oentianece] and Scrojphularinece are on the 

 other hand much fewer, but the imion is much closer. With 

 Scro2hula7nnece in particular, although the general affinity is more 

 remote, the few intermediate genera and species are intermediate 

 in every respect, in habit as in technical character. The main 

 distinction, the presence of stipules in Loganiacece, disappears very 

 gradually, and the difficulty of drawing the line is the greater from 

 there being no general habit or family resemblance to unite the 

 several members of the Loganiacece. A somewhat arbitrary deci- 

 sion is therefore here unavoidable, and we can only direct our best 

 endeavours to the adoption of that demarcation which shall inter- 

 fere the least with the circumscription of the allied orders. 



Opposite leaves, interpetiolar stipules (represented occasionally 

 by a mere line connecting the petioles), epipetalous stamens alter- 

 natmg with the lobes of a regular gamopetalous corolla, a free 

 ovary divided into two or rarely more cells, a style cleft at the 

 top into aa many lobes, an axile placentation and albuminous 

 seeds with a comparatively small straight embryo, may be said to 

 be the main features oi Loganiacecd \ and wherever these characters 

 can be undoubtedly recognized, there will be no difficulty as to the 

 identification of the order. But where the stipule^ become rudi- 

 mentary, the case is very different, and secondary characters, such 

 as aestivation of the corolla, regularity in the flower, dehiscence of 

 t^e capsule, peculiarities of placentation variously combined, must 

 be resorted to, as wnll be seen when we come to examine into the 

 vanous tribes into which the order is divided. 



In DeCandolle's ' Prodromua ' eleven distinct tribes are adopted, 



but little of that philosophical method which usually chd- 

 J^terized his systematical works. This was, however, the natural 

 consequence of the process by which the amalgamation wa« formed. 

 A number of detached genera rejected from very different orders 

 were provisionaUy associated with others which had been published 

 V various botanists as separate families ; and as the materials he 

 possessed did not admit of his taking a comprehensive view of the 

 ^tole, he thought it necessary to retain as tribes whatever had 



showinjr 



^ - 



