OF CENTRAL AFRICA. 285 



parts in question : and I may remark that similar observa- 

 tions on certain genera of Caryophylleae, especially Diantlius, 

 Lychnis, and Silene, clearly establish the analogy between 

 their petals and those of Reseda. 



I am aware that it has lately been proposed to include 

 Batisca in Resedacese, to which it is nearly similar in the 

 structure of its ovarium, as M. de Jussieu has long since 

 remarked. But this is the only point of resemblance be- 

 tween them ; for the calyx of Datisca is certainly adherent, 

 and in most of its other characters it diifers widely both 

 from Reseda and from every other genus yet published. 

 Among the numerous discoveries made by Dr. Horsfield in 

 Java, there is a genus (Tetrameles nob), however, mani- 

 festly related to Datisca, and remarkable in the regular 

 quarternary division of every part of its dicecious flowers. 

 These two genera form an order very different from every 

 other yet established, and which may be named Da- 



TISCEiE. 



Caryophylle^. Five species only of this family were 

 collected near Tripoli, none of which are new. 



Of Zygophylle^, six species exist in Dr. Oudney's her- 

 barium, namely, Tribulus terrestris, found in Bornou ; 

 Fagonia cretica, from Tripoli to Benioleed ; Fagonia 

 arabica, at Aghedem ; Fagonia Oudneyi 7ioh. with Zygo- 

 phyllum simplex in Fezzan ; and Zygophyllum album 

 everywhere in the desert. 



This family, so distinct in habit from Diosmese or 

 Rutacese, with which it was formerly united, is not 

 easily characterised by any very obvious or constant pecu- 

 liarities in its parts of fructification. 



The distinguishing characters in its vegetation or habit 

 are the leaves being constantly opposite, with lateral or psi 

 intermediate stipulse, being generally compound, and 

 always destitute of the pellucid glands, which universally 

 exist in true Diosmese, though not in all Rutaceas pro- 

 perly so called. 



M. Adrien de Jussieu, in his late very excellent Memoir 

 on the great order or class Rutacese, in distinguishing 



