263 Mr. J. Miers on the Bignoniacese." 



Priva splits into two halves, each 2-celled, with erect seeds, 

 thus offering much analogy with the fruit of Sesamacece : the 

 seeds in both cases are exalbuminous, with an embryo of similar 

 form. The capsule, also, is often echinate or cornute in Priva 

 and Tamonea, as in Sesamum and Ceratotheca. In habit there 

 is also much accordance between Priva and Sesamum. 



Tourretia has always been considered as a doubtful genus of 

 the BiynoniacecB ; but if the structure of the fruit be correctly 

 described, it evidently belongs to Sesamacece, as Fenzl long since 

 indicated * : it has a 4-celled capsule, which opens only at the 

 apex by a gaping transverse fissure, greatly after the manner of 

 dehiscence in Sesamum ; and the seeds are affixed to a central 

 axis, as in that genus, and are erect, not transverse as in Bigno- 

 niacece, showing that this structure results from the combination 

 of four carpels, whose placentiferous margins meet in the axis — 

 a structure quite incompatible with Bignoniacea. In regard to 

 its echinate fruit, the retrorsely uncinate spines that cover its 

 capsule are precisely analogous to those of Harpagophytum, 

 which, from its axile placentation, certainly belongs to Sesama- 

 cea, and not to Pedaliacea (we find a corresponding tendency 

 to the production of spines in the capsules of Ceratotheca and 

 Sporledera) ; and its seeds have a similar rugosely expanded 

 border. The principal difference is in the habit of the plant, 

 which, though herbaceous, has conjugate leaves, its leaflets 

 being again palmately divided ; and they have an intermediate 

 cirrhus, which is also pinnately branched. Harpagophytum and 

 Sesamum have tripartite or palmatifid leaves, lacniiately divided, 

 but they have no cirrhus. But as Eccremocarpus and Calampelis 

 are admitted into the Bignoniacece, and must be associated with 

 Jacaranda, many of the species of which form large trees with 

 ecirrhose pinnated leaves, we cannot refuse to admit Tourretia 

 into the Sesamea because of the presence of a cirrhus. The 

 seeds of Tourretia are alike in shape and position, and have the 

 same kind of cristate margin as in Sesamopteris. 



In the tribe Bignoniece, the cells of the ovary are anterior and 

 posterior to the axis of inflorescence ; but the four lines of pla- 

 centation stand laterally right and left of the same line of axis. 

 In the Catalpece, on the contrary, the cells of the ovary are right 

 and left, while the lines of placentation are upon the transverse 

 dissepiment, which has a direction radiating from the axis of 

 inflorescence. In the Platycarpece, where the ovary is also 

 2-celled, the placentations being on the dissepiment, the cells 

 as well as the piacentie preserve tLc same dextral and sinistral 

 aspect. In the Eccremocarpece, where the ovary is unilocular, 



* Fenzl, Denksoh. Regensb. iii. 211 ; A. DeCandolle, Prodr. ix. 236 in 

 adnotat. 



