78 



LOWER liOCKNK FLOliAS OK SOUTIIEASTEKX Ndlilll A.M KlUCA. 



Tho ixbsonro of tlio BiiJ[jiU(ipsiil;il(>s, SaiTacoui- 

 iJos, and 0])imtiali's is not. mnarkablc, sinew 

 th(\y aro all spt'cializod typi^s and the rather 

 uniform habitats of the cacti and their rela- 

 tively modern evolution both consph-c to 

 eliminate them from Eocene coastal floras. 

 The presence of the primitive Casuarinalos 

 and Pip(>riiles might b(> expected, especially 

 since there is a well-marked Piper-like form in 

 the Upper Cretaceous of Alabama. The Sali- 

 cales, though prevailingly temperate forms, are 

 abundantly represented in the Upper Ci"eta- 

 ceous floras of the embayment area, and the 

 Santalales have also been recorded from the 

 American Upper Cretaceous and are present 

 in the European Tertiary. 



Those alliances of Gamopetala3 which are not 

 present in the Wdcox are mainly the great mod- 

 ern and Temperate Zone groups. For example, 

 there are no Wilcox species of EricsiJes, Labi- 

 atse, Convolvulacefe, Bignoniacca?, Scrophu- 

 lariacese, Plantaginales, Valerianales, or Cam- 

 panulales, thus proving not only the essential 

 modernness of the evolution of the Compositae 

 but firmly establishing the subtropical rather 

 than temperate character of the Wilcox flora. 

 The fruit described as Carpolithits hyoseriti- 

 formis is probably referable to the ConipositiB. 



The larger families of the Dicotyledons in the 

 Wilcox flora are the following: Lauracete (30 

 species), Csesalpiniacese (26 species), Moracese 

 (23 .species), Papdionaceae (22 species), Rliam- 

 naceae (14 species), Sapindacese (13 species), 

 Sapotacese (12 species), Myrtacese and Mimo- 

 sacese (11 species each), Combretacese and 

 Anacardiacese (9 species each), Juglanehicere (8 

 species), Celastracese (7 species), and tho Pro- 

 teacea3 and Apocynacese (6 species each). 



The largest single genus is Ficus, which has 

 18 species. Cassia has 12 species; Sapindus 9; 

 Gleditsiophyllum 8 ; Oreodaphne, Sophora, and 

 Anacardites 7 each; Cinuamomum, Nectandra, 

 Rhamnus, Myrcia, and Bumelia 6 each; and 

 Celastrus, Dillenites, and ApocynophyUum, 5 

 each. Ten species are referred to the form 

 genus Carpolithus, and tliis number could 

 readily be greatly increased if all tlio unidenti- 

 fied seeds w(>re named and described. 



The ameutiferoiis families, in accordance 

 with their Upper Cretaceous deployment and 

 their undoubtedly primitive and not reduced 

 character, arc represented in tlie Wili-ox flora 

 by 14 species, some of which are abundant. 



Tile Juglandides ' are represented in the 

 Wilcox by three species of Juglans, only oiu' of 

 which, Juglans schimperi, is at all <-((iiiin(in ; ])y 

 a doubtfully determined species of llicoria; by 

 tlu'ee well-marked species of Engc^liiardtia; 

 and by an extinct type, Paraengelliar(hia, of a 

 habit similar to that of Engelhardtia. 



The genus Juglans is one of the earliest ()f the 

 still-existing dicotyledonous genera to appear 

 in the fossil record, and it is continuously repre- 

 sented in f ossd floras from the middle Cretaceous 

 to the present. Tiiere are about 25 Eocene 

 species of walnut, which range during that pe- 

 riod from the Gulf region to Alaska and Green- 

 land, and these forms are also present in tiie 

 tropicid forests of the Egyptian Fayum in tlie 

 early Oligocene. The accompanying sketch 

 map (fig. 4) shows the existing distribution of 

 Juglans and its known former range. This 

 map, which shows the outlying existing species 

 in the West Indies and under the Equator in 

 South America, indicates that in spite of the 

 northward range of the Asiatic species in Man- 

 churia and of some of the North American 

 species into New England and southern Onta- 

 rio, the progenitors were at least subtropical 

 types, a fact corroborated by their foliar cliarac- 

 ters, since it is well known that compound 

 leaves indicate tropical ancestry. This is 

 abundantly proved for Juglans by its associates 

 in the fossil floras in which it is represented. 



The genus Engelhardtia - is one of the most 

 interesting Wih^ox genera. In the first place 

 the identification of its leaves is corroborated 

 by two varieties of characteristic winged fruits. 

 The genus was descrilied by Leschen in 1 825 

 and contains about 10 species in the south- 

 eastern Asiatic area, ranging from tlie iioi'th- 

 western IlimiJayan region, where they ewtcnd a 

 short distance north of the Tropic of Cancer, 

 through Farther India and Burma to Java and 

 the Philippines. The pistillate flowers are 

 small and are grouped in paniculate spikes. 

 They develop into small drupelike fruils, each 

 of which is connate at the base to a large ex- 

 panded trialat(i involucre. 



A single liltl(--l<no\vn sp(>cies, rarely I'ejjre- 

 sented in even the larger herbaria, occurs in 

 Central America and is the type anti only spe- 

 cies of the genus Oreomunnca of Oersted. 



■ Berry, E. W., Notes on tho geological history of Iho wahiuls and 

 hickories: Plant WorUI, vol. 15, pp. 22.0-2411, 1912. 



2 Berry, K. W., Am, Jour. i3ci.,4th ser.,vol. 31, pp. 491-lW, 1911: IMant 

 World, vol. 15, pp. 2!4-2.'i8, figs. 3, 4, 1912. 



