146 



LOWER EOCENE FLORAS OF SOUTHEASTERN NORTH AMERICA. 



Dewalquea. 



Dicksonia. 



Don-anthites. 



Drj^opterites. 



Eorhamnidium. 



Equisetum. 



Geinitzia. 



Gleichenia. 



Hymena'a. 



Jungermannites. 



Kalmia. 



Liriodendron. 



Liriodendropsis. 



Malapa^nna. 



Manihotites. 



Maratfia. 



JleniBpermites. 



M\Tsine. 



Palasocassia. 



Panax. 



Persoonia. 



Pinus. 



Piperites. 



Plataiius. 



Podozamifes. 



Populus. 



Protodammara. 



Protophylli)cladiis. 



Pterospermites. 



SalLx. 



Sapotacites. 



Sassafras. 



Sequoia. 



Tricalycites. 



Ttimion. 



Widdrinsitonitea. 



The most prominent of these forms with re- 

 gard to plant evohition are the gynmospemious 

 genera Abietites, Androvettia, Araucaria, 

 Brachyphylhim, Cephalotaxospennum, Cun- 

 ninghaniites, Cycaduiocarpus, Danunara, Gei- 

 nitzia, Pinus, Podozamites, Protodammara, 

 Protophyllocladus, Sequoia, Tumion, and Wid- 

 dringtonites. Upper Cretaceous genera which 

 were expected in the Wilcox but which have 

 not been discovered are Bauhinia, CoccuJus, 

 Gleichenia, Hymena^a, Liriodendropsis, Marat- 

 tia, MjTsine, Pterospermites, and Sassafras. 



The following 24 genera recorded from the 

 Upper Cretaceous of the embajnnent are also 

 found in the Wilcox: Cassia, Ciimamomum, 

 CitrophyUum, Cordia, CrotonophyUum, Dios- 

 pyros, Eugenia, Ficus, Grewiopsis, Ilex, Inga, 

 Juglans, Lcguminosites, Magnolia, Myrica, 

 Nyssa, Oreodaphne, Paliurus, Persea, Prote- 

 oides, Rhanuius, Sabahtes, Sapindus, and Zizy- 

 phus. It is thus evident that one of the strik- 

 ing features of difference between the two floras 

 is the ehmination of the Mesozoic coniferous 

 types like Androvettia, BrachyphyUum, Cyca- 

 dinocarpus, Dammara, Geinitzia, Podozamites, 

 Protodammara, Protophyllocladus, and Wid- 

 dringtonites, and the withdrawal from this 

 region, more or less in response to climatic 

 conditions, of Araucaria, Pinus, Andromeda, 

 Liriodcndron, Malapcenna, Menispermites, Per- 

 soonia, Platanus, Salix, and the like. 



There is, however, a well-delined basis for 

 the statement that the Eocene floras were 

 modernized, whic^h is furnished by the follow- 

 ing 62 Wilcox genera, all but (5 of which an^ 

 dicotyledonous and of modern aspect, that 

 have not been fountl in the Upper Cretaceous: 



Caenomyces. 

 Meniphylloidos. 

 Ghqifosfrulnis. 

 Taxodium. 

 Chamsedorea. 

 Canna. 

 Hicoria. 



Paraengelhardtia. 

 Engelhardtia. 

 Pseudolmedia. 

 Paheodendron. 

 Knight iophy Hum. 

 Aristolochia. 

 Coccolobis. 

 Anona. 

 Aaimina. 

 Mespilodaphne. 

 Cryptocarya. 

 Capparis. 

 Chrysobalanus. 

 Pithfcololiium. 

 Cere is. 

 Ctesalpinia. 

 Gleditsiophyllum. 

 •Sophora. 

 Canavalia. 

 Fagara. 

 Simaruba. 

 Carapa. 

 Cedrela. 

 Vanfanea. 



Hirsea. 



Banisteria. 



Drypptes. 



Meto])ium. 



Anaeardites. 



Heterocalyx. 



Maytenus. 



Cupanites. 



Dodouoea. 



Reynosia. 



Sterculiocarpus. 



Bombacites. 



Dillcnifes. 



Ternstroemites. 



Myrcia. 



Calyptranthes. 



Laguiicularia. 



Combretum. 



Terniinalia. 



Conocarpus. 



Melastoniites. 



Icacorea. 



Sideroxylon. 



Chrysophyllum. 



Mimusops. 



Osmanthus. 



Citharexylon. 



Avicennia. 



Solanites. 



Exostema. 



Guettarda. 



Some of these have Cretaceous relatives. 

 For example, Capparis is represented by the 

 Tuscaloosa species of Capparites, Conocarpus 

 is represented ha the Tuscaloosa by Conocar- 

 pites, Sapotacites represents Upper Cretaceous 

 Sapotaceoe, and some of the numerous Upper 

 Cretaceous species of CelastrophyUum may 

 represent the Wilcox genus Ternstroemites. 



It is obvious without further discussion that 

 the Wilcox flora is decidedly more modern than 

 not only the Upper Cretaceous floras of the 

 embayment area but even the youngest known 

 Upper Cretaceous floras represented by the 

 Laramie flora of North America and the Maes- 

 trichtian flora of Europe and is ahnost wholly 

 unlike those floras. The flora of the Wilcox is, 

 then, in complete accord with the stratigraphy 

 and paleozoology in indicating that it is 

 decidedly post-Mesozoic and much younger 

 than any known Upper Cretaceous floras. 



KELATION TO THE MIDWAY (?) FLORA. 



The Midway (?) flora is so small tliut it 

 afl'ords little liasis for comparison. However, 

 none of its types are Cretaceous and 30 per 

 cent of its small number of species are common 



