

* 



A. 



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OF RIJBIACE^ TN TROPICAL AFRICA. 257 



it is split down two opposite sides ; and in a species of each of the 

 genera Randia and Cephaelis the limb is spathaceous. The lobes 

 are more or less accrescent or foliaceous in Temnocalyx, Penta- 

 loncJia^ Heinsia^ Dictyandra^ Leptactina^ Amaralia, Pentanisia^ 

 Cuviera^ AntJiospermum, and Oaillonia^ and in some species of the 

 genera Sandia, Gardenia, Fadogia, and Psilanthus, The limb of 

 the calyx is, in some genera, reduced to little more than a slightly 

 lobed ring. 



The aestivation of the calyx is various, but most frequently open ; 

 the principal exceptions are as follows : — In the genus Lampro- 

 thamnus and in a species oiPavetta the calyx-lobes are imbricated 

 in aestivation ; in the latter case, however, they are occasionally 

 contorted. The aestivation is contorted in the same direction as 

 in the corolla (homotropous) in the genera Dictyandra^ LeptacHna^ 

 and in two species of the genus Tarenna (T. nitidulay var. Afzelii, 



and T, congensis) ; it is contorted in the reverse direction (hete- 

 rotropous) in the genus Amaralia, 



8. Differences in tlie Inflorescence and Bracts. 



There is considerable variation in the inflorescence. The pri- 

 mary division of the tribe Gardenieae depends upon the nature of 

 the inflorescence, that is to say, whether it is terminal or axillary ; 

 among the former division of the tribe, however, are some genera 

 with the inflorescence terminating in abbreviated, lateral branches. 

 Again, the genera of the tribe Mussaende® are classified on the 

 same principle ; and one genus of this latter tribe is remarkable 

 for having its inflorescence enclosed in one or two campanulateor 

 connate bracts. The tribe Naucleea? is characterized by flowers 

 confluent or collected in compact heads ; and some of the genera 

 of this tribe are mutually distinguished by the presence or ab- 

 sence of paleaceous bracteoles between the several flowers. The 

 structure of the inflorescence also determines to a great extent the 

 classification of the genera of the tribe Psychotrieae ; and invo- 

 lucrate flowers occur in two of the genera of this tribe. 



The inflorescence is corymbose in numerous genera ; it is capi- 

 tate in several, as, for instance, in addition to those already 

 alluded to, Sahicea, Cephaelis, Trichostachjs, Spermacoce, Hypode- 

 matium, Octodon, Bichardia, and Mitracarpum, as well as in a 

 section oi Psycliotria and in certain species of other genera ; in 

 Butidea thecapitulaare arranged in brachiate terminal panicles ; 

 it is spicate fla Hymenodictyon, Otomeria, Oaillonia, and in some 

 species of Bertiera (in one species of the last genus the spikes are 



