OF PLANTS CALLED COMPOSITE. 279 



ill any natural family may with some confidence be pre- 

 dicted by an examination of those genera where the number 

 is complete. 



Wherever the separation of sexes takes place, it may be 

 assumed that the female flower is the more perfect pro- 

 duction. And if this be admitted, where both sexes exist 

 in the same simple spike the female should be found at its 

 base, or where expansion commences, which is almost 

 uniformly the case. For the same reason, in the trifid or 

 trichotomous inflorescence, the female should be placed in 

 the centre, which is also generally the fact.^ 



This connexion between prsecocity and perfection of deve- 

 lopment is even more constant than the order of expansion 

 in certain forms of inflorescence; as it is found to extend to 

 several of the exceptions to this order. 



Thus in the apparently simple spike of Poterium, where 

 the order of expansion is descendent, the female flowers 

 occupy the upper part of the spike; and this relation also m 

 exists in the more compound inflorescence of Bicinus, 

 Sipkonia, and Celtis, in which the order of expansion is 

 equally inverted. 



It may seem rather paradoxical to select Euphorbia as an 

 example of the same relation ; this genus being considered 

 by Linnaeus, and the greater part of the botanists who have 

 adopted his system, as having a dodecandrous hermaphro- 

 dite flower. We have already, however, I believe, sufficient 

 evidence that this supposed hermaphrodite flower is in 

 reality formed of several monandrous male flowers surround- 

 ing a single female.^ 



1 To this order the most remarkable exception occurs in Begonia, in which 

 the male flowers are central, and expand long before the lateral female flowers. 



2 To the arguments 1 have adduced (in my Remarks on the Botany of New 

 Holland \vol. i, p. 28]) in support of this opinion, I am now enabled to add 

 the more direct proof derived from certain species of Euphorbia itself, in which 

 the female flower is furnished with a manifest calyx. I have formerly observed, 

 that in a few cases the footstalk of the ovarium is dilated and obscurely lobed 

 at top ; but in the species now referred to it terminates in three distinct and 

 equal lobes of considerable length, and which being regularly opposite to the 

 cells of the capsule may be compared to the three outer foliola of the perian- 

 thium of Phi/ilanthus, between which and the cells of the capsule the same rela- 

 tion exists. This calyx is most remarkable in an undescribed species of Euphorbia 

 from the coast of Patagonia, in the Herbarium of Sir Joseph Banks; but it is. 

 observable, though less distinct, in E. punicea and several other species. 



