246 



MORPHOLOGY OF THE ANGIOSPERMS 



quarter of the twentieth century, even though the appendicular theory 

 had been strongly supported by Van Tieghem with anatomical evi- 

 dence. In the later decades of the twentieth century, with much more 

 information available from anatomy and ontogeny and a broader un- 

 derstanding of the effects of congenital fusion on anatomical structure 

 and ontogenetic development, it has become clear that the inferior 

 ovary has developed in two morphologically different ways — by adna- 

 tion of floral appendages and by the hollowing of the axis tip. 



Fig. 94. Diagrams of longitudinal sections of ericaceous flowers showing evidence 

 of appendicular nature of the inferior ovary by adnation of outer floral whorls to 

 the ovary. Adnation increasing in extent, including fusion of the vascular supplies 

 of all organs; the trunk systems so formed suggestive of stelar bundles. A, Pijrola 

 secunda; B, Andromeda gluucopJujlla; C, Qaijlussacia jrondosa; D, Vacciniitm 

 vacillatis; E, V. pennstjlvaniciim; F, V. macrocarpon. do, dorsal carpellary bundle; 

 Ds, dorsal sepal trace; p, petal trace; R, receptacle; st, stamen trace. {After Eames, 

 1931.) 



Like many other structural modifications, the inferior ovary has de- 

 veloped independently in many taxa. Evidence of independent origin 

 is found in many families. All stages in the adnation of the appendages 

 are present in the Ericaceae (Fig. 94), Rosaceae, Amaryllidaceae; other 

 families show both superior and inferior ovaries, with or without transi- 

 tional stages. In the Iridaceae, Isophi/sis (Hewarclia) has a superior 

 ovary; other genera, an inferior ovary. In the Gesneriaceae, Gloxinia 

 has a superior; other genera, an inferior ovary. In the Nymphaeaceae, 

 Nelumbo and Nuphar have superior ovaries; Nymphaea and Victoria, 



