448 



BOTANY 



The androecium springs directly from the floral axis, or it is 

 adnate to other portions of the flower, in particular to the perianth. 



Great weight was formerly attached by systematists to the mode of insertion of 

 the andrcecium. It was then customary to distinguish Thalamiflorae, Corolli- 



florae, or Calyaiflorae, according as the stamens 

 were inserted on the receptacle, the corolla, or 

 the calyx. Oalyciflorae, as a matter of fact, do 

 not occur, as in such cases the supposed calyx is 

 in reality the expanded floral axis. 



The term staminodes is applied to 

 sterile members of the androecium which 

 produce no pollen, and are either abortive 

 and functionless (e.g. Linum) or are peta- 

 loid in appearance, and serve as organs 

 of attraction (e.g. Zingiberaceae). Phylo- 

 fig. sn-Ammm officios flower genetically they are to be re garded as 



cut through longitudinally; n, . ° . J ■> ° 



epicaiyx ; 4, calyx ; c, corolla ; d, derived from normal stamens. 



andrcecium. (After Berg and The GYNGECIUM IS always the ter- 



S0HM.r.T, magnified.) ^^ ebmeban of the fl()wer> occupying 



the apex of the floral axis. It is either composed of separate 

 members, apocarpous (Fig. 378, A), or the members are united, 

 SYNCARPOUS (B, D). In the first case the margins of each carpel 

 are so joined together that each forms a distinct ovary or closed 

 cavity containing the ovules. The carpels of a syncarpous gyn- 



Fig. 378. — Different forms of gyncecia. A, Of Aconituui Napellus ; B } of Linum usitatissimum ; C, of 

 Nicotiana rustica ; D, style and stigma of Achillea Millefolium ; f, ovary ; g, style ; n, stigma. 

 (After Berg and Schmidt, magnified.) 



oecium, on the other hand, are coherent and form collectively a single 

 ovary, which may be either plurilocular when the coherent margins 

 of the carpels extend to the axis, or unilocular if the carpels cohere 

 simply by their edges, and do not turn inward, or only slightly. 



The double walls or dissepiments of a plurilocular ovary, formed 

 by the inwardly projecting margins of the coherent carpels, are dis- 



