356 



NATURAL HISTORY OF PLANTS. 



Brexia madagascariensis. 



gamosepalous at the base, with five deep very caducous lobes of 

 quincuncial pignoration ; a corolla of five alternating petals, 1 twisted 



or imbricated in the bud; 

 five alternipetalous stamens, 

 whose filaments are united at 

 the base by a disk of five al- 

 ternate lobes cut up into un- 

 equal strips. 2 The anthers 

 are two-celled introrse, of 

 longitudinal dehiscence. The 

 gynseceum is superior ; it con- 

 sists of a pentagonal ovary with 

 its angles superposed to the 

 stamens, tapering above into a 

 cylindrical style, whose apex 

 is divided into five stigma- 

 tiferous lobes. 3 The ovary 

 contains five oppositipetalous 

 cells, complete or incomplete, 

 in the ventral angle of which 

 is a placenta bearing two vert- 

 ical rows of anatropous ovules. The fruit is a drupe of which 

 the outer layer finally becomes hard, and it contains numerous 

 angular seeds. These have a large embryo with a short radicle 

 and fleshy cotyledons, surrounded by a very thin layer of fleshy 

 albumen. Brexia comprises for most authors a pretty large number 

 of species 4 of glabrous shrubs from Madagascar ; but they should 

 no doubt be reduced to one or two species, very variable in 



Fig. 412. 

 Flowering branch. 



15, 16. — H. Bn,, in Adansonia, v. 290; vi. 15 ; 

 in Payer Fam. Nat., 349. — B. H., Gen., 645, n. 

 40. — Schnizl., Iconogr., xv. t. 170. — Lem. & 

 Dcne,, Traite Gen., 264, 265. — Venana Lame., 

 III., ii. 99, t. 131. 



1 They are unsymmetrical at tbe base, ons 

 side being prolonged into a sort of descending 

 auricle. They are inserted outside a cupuliform 

 ring formed by the united bases of the stamens 

 and the lobes of the disk. 



2 On either side of the base of each filament is 

 one of these strips, larger than the rest. 



3 We have shown (in Adansonia, v. 291) that 



the placentas, whether they touch by their ventral 

 angle or not, here form each a dihedral angle, 

 which is prolonged through the hollow tube of the 

 style ; and becoming covered with papilla? at the 

 blunt superior extremity, they form five little 

 stigmatic lobes alternate with the cells of the 

 ovary, and surrounded, as in the Heaths, by a 

 little ring formed by the rim of the stylar tube. 

 This arrangement is still more marked in Rotissea. 

 4 Li>-dl., in Bot. Beg., t. 730, 872.— Tr/L., in 

 Ann. Sc. Nat., ser. 4, viii. 158. — Olit., in Fl. 

 Trop. Afr., ii. 385.— W.ALP., Ann., vii. 907. 



