196 :\rANUAL OF BOTANY 



spurious dissepiments of Cassia fistula, Astragalus, Phaca, 

 and Oxytropis are all examples of such formations in simple 

 ovaries. 



We have now to consider the formation of the compound 

 ovary which presents but one ca/oity, instead of two or more, 

 as im that just alluded to. Such an ovary is formed either by 

 the union of the contiguous margins of the flattened open 

 ovaries of the carpels of which it is composed, as in the 

 Mignonette (fig. 424) ; or by the union of carpels the margins 

 of which are only partially folded inwards, so that all their 

 cavities communicate in the centre. An ovary formed in either 

 of these ways is unilocular though compound, as in the Orchis 

 (fig. 425) and Poppy (fig. 426). 



Having now described the parts, nature, and structure of 

 the carpel, and of the gynoeoium or pistil generally, we proceed 

 in the next place to allude separately to the constituent parts of 

 the carpel, whether it be free or combined — namely, the ovary, 

 style, and stigma. 



1. The Ovaky. — The ovary, as already mentioned, is called 

 compound when it is composed of two or more ovaries com- 

 bined together; on the other hand, it 'is simple when it 

 constitutes the lower part of a simple pistil (fig. 396, o), or 

 of one of the carpels of an apocarpous pistil (fig. 284). It 

 should be noticed, therefore, that the terms simple pistil and 

 simple ovary are not in all cases synonymous terms ; a 

 pistil is only said to be simple (figs. 396 and 406) when it is 

 formed of but one carpel, the terms pistil and carpel being then 

 mutually convertible ; but an ovary is simple, as just noticed, 

 whether it formB part of a simple pistil, as in Leguminous 

 plants generally (fig. 406), or of one of the carpels of an apo- 

 carpous pistil, as in the Stonecrop (fig. 284) . 



Generally speaking, the ovary is sessile upon the thalamus, 

 the carpellary leaves out of which it is formed having no stalks. 

 In rare cases, however, the ovary is more or less elevated above 

 the outer whorls, when it is said to be stalked or stipitate, as in 

 Dictainnus (fig. 427, g) and Dianthus (fig. 405, g) ; this stalk 

 has received the name of gynophore. 



The ovary, whether simple or compound, may be either 

 united with the calyx or free from it. In the former case, as 

 in the Mj'rtle (fig. 273), it is inferior or adherent, and the 

 calyx is superior; in the latter, as in Dictammus (fig. 427)'; 

 it is superior or free, and the calyx is inferior. In some 

 flowers the ovary is hut partially adherent to the calyx, as in 



