PROFKSSOE OLIVER OX SOUTH AmiCAN BRUNIACEiE. 331 



are numer- 



Memorandum on the Genus Thamnea, Solander, and other Bru- 

 niacese contained in the South African Hprbarium of the late 

 Dr. Burchell, T.L.S. By Professor Oliver, P.E.S., T.L.S., 

 Keeper of the Kew Herbarium. 



[Kead March 1, 1866.] 



In the Cape collections of the late Dr. Burchell there 

 ous specimens of four species of the curious and little-known 

 genus Thamnea^ Solander, including specimens of the only species 

 hitherto described — T, uniflora. Thamnea was first made known 

 by M. Brongniart in 1826 (Ann. Sc.Naturelles, ser.l. t. viii.p.386). 

 In his remarks upon it he called attention to the remarkable 

 structure of its ovary, which he described as unilocular, with a 

 slender central column, enlarged at the apex into a disciform pla- 

 centa, round which are suspended, apparently, ten ovules. This 

 unilocular condition he rightly ascribed to the " destruction des 

 cJoisons des loges\' and from the (apparent) number of ovules he 

 inferred that the ovary was probably normally 5-celled, each cell 

 being biovulate, the number of ovules in each cell of the ovary 

 in other genera of Bruniacese never exceeding two. 



Dr. Burcbell's specimens enable me to ascertain satisfactorily 

 that Thamnea is dicarpellary *. In two of the species {T.depressa 

 and T. hirtella) the ovary is either wholly bilocular at the time of 

 flowering, or nearly so. In T. uniflora I find two distinct opposite 

 ridges On either side of the central column upon the underside 

 of the plane top of the ovary, indicating the suppressed dissepi- 

 ment. In T, gracilis^ on the other hand, there is a similar ridge 

 upon but one side of the ovarian cavity, and certainly no trace of 

 it on the opposite side. How to explain such a condition in the 

 absence of any obliquity in the flower indicating it to be mono- 

 carpellary I cannot tell. Jn none of the species do the ovules 

 appear to exceed four to each cell^ m two species they are gemi- 

 iiate. All the species agree in their solitary terminal flowers 

 (sometimes however upon very short lateral ramuli), in their 

 ■wholly inferior plane-topped turbinate ovary, elongate simple 

 style, and (in three of the species) one-seeded fruit. The species 

 of Thamnea may be described as foUows : 



( 



Sc. Nat. s^r. 1 . t. viii, Erecta, 



- r - - - ' 7 ^ 



glaberrima, ramulis strictis, foliis arete adjjressis ioibricatis lanceolatis 



* Dr. Sender, in • Flora Capensis,' ii. 324, pays 1- (or 5-2-) celled. 



