534 



PHANEROGAMS. 



unlike those produced by the hiteral section; this diagram is, hke those in Figs. 378 

 ii, Cand 379, zygomorphic, but is doubly while these are only singly symmetrical. 



The symmetry of mature unfolded flowers is indeed usually connected genetically 

 with the relations of symmetry of the diagram (which represents only the position and 

 number of the parts); as will be made clear by a comparison of Pigs. 385 and 387 with 

 Fig. 379 ^. But inasmuch as the entire form of the mature flower is essentially deter- 

 mined by the shape, size, torsion, and curvature of the separate parts, these circum- 

 stances also exert a preponderating influence on the relations of symmetry of the open 



Fig. 385. — Zygomorphic flower of Cohantica Schiedeana : A entire flower after removal of two sepals ; E andruecium ; 

 C gynasceum ; D the coherent anthers magnified and seen from behind ; E horizontal section of the ovary ; F diagram ; 

 a anthers, n stigma, g style, fk ovary, d the stamiiiode developed into a nectary, // the lateral oblique placentae. 



f ower, and to such a degree that even flowers that have their parts arranged spirally 

 may become monosymmetrically zygomorphic in reference to their entire form, as is 

 the case to a high degree, for example, in Aconitum and Delphinium. It must however 

 be observed that the zygomorphism of the flower is here brought about principally or 

 entirely by the calyx and corolla, the spiral arrangement of which may perhaps still be 

 doubtful, but which always occupy so narrow a zone on the receptacle that their position 

 may be considered practically to be verticillate. If, on the other hand, the floral axis is 

 sufliciently elongated to show that the arrangement is a distinctly ascending spiral one, 

 as in the perianth and androecium of Nymphaea and the androecium and gynaeceum of 



