32 The Ohio Journal of Science [Vol. XX, No. 2, 



The higher relatives of the lilies show few monosporangiate 

 flowers, probably because of the very general reduction of the 

 stamens, commonly having but one fertile stamen present. 



Dicotyls. 



The Thalamiflorae are typically bisporangiate, but diecious 

 species and genera appear at various levels. Magnolia is 

 bisporangiate, and certain Thalictrums, as already described 

 are diecious. The common Mallows are bisporangiate like the 

 genera, Malva and Alth^a, while their near relative Napsea 

 dioica L., is diecious. Carica papaya L. one of the most advanced 

 members of the group, is also diecious. 



Among the Centrospermse, some species of Lychnis are 

 bisporangiate and some, like L. alba Mill, and L. dioica L., are 

 diecious. The same relationship can be found among the higher 

 types. For instance, Chenopodium has bisporangiate flowers 

 while the species of Amaranthus grade from the monecious con- 

 dition to extreme dieciousness. 



Among the lower Calycifloras, Opulaster and Spirsea are 

 bisporangiate and Aruncus aruncus (L) Karst. is diecious with 

 prominent vestiges of the opposite sets of organs. Farther along 

 the evolutionary scale we find Cercis and Cassia bisporangiate 

 while the related Gymnocladus dioica (L) Koch, is diecious with 

 prominent vestiges. As we pass to the advanced members of 

 the group, such genera as Acer become conspicuous which not 

 only show their close relationship to bisporangiate genera but 

 the various species present ' a close gradation of degrees of 

 intensity of the monosporangiate condition up to complete 

 dieciousness in Acer negundo L. 



The Amentiferae have bisporangiate flowers in the less 

 specialized groups, but a large per cent of the species are 

 monecious or diecious. Extreme examples of diecious species 

 .are Cannabis sativa L., Myreca gale L., and Populus deltoides 

 Marsh. 



Among the Myrtiflorae, the evening primroses are bispor- 

 angiate while the related Haloragidaceae have bisporangiate, 

 monecious, and diecious species. 



The lower families of the Heteromerae, like the Ericaceae, are 

 usually bisporangiate while the more advanced Ebenaceae 

 rarely have bisporangiate flowers but are usually completely 

 diecious, or imperfectly diecious like Diospyros virginiana L. 



