COMl'OSITIOX OF THE FLORA. 



127 



the form {jenus Sapotacites. Kcid refers a seed 

 from the PUoceiie of Limburg to this genus. 



The gemis Sitl(>roxylon Liiuio, which inchules 

 about SO existing species m the oriental Tropics 

 and about 15 in the American Tropics, is rep- 

 resented by 2 species in the WUcox flora, which 

 are the oldest thus far discovered. To this 

 genus have been referred 4 Ohgocene and 1 or 

 2 Miocene species from Europe. 



Isonandra Wright, a small modern genus of 

 the Malayan region, is represented in the Ter- 

 tiary of Borneo by Isonandrophyllum Geyler. 

 The genus Achras Linne (Sapota Plumier), now 

 monotypic in tropical America, contains 3 spe- 

 cies in the European Miocene. Labatia 

 Swartz, which includes 6 existing species in 

 the American Tropics, has been doubtfully 

 determined in the Miocene of Prussia and Italy. 

 Felix has descrihed two forms of petrified wood, 

 which he refers to this family under the name 

 Sapotoxylon, one species from Germany and 

 the other from an unknown locality and hori- 

 zon. The genus CalophyUum Pierre is repre- 

 sented by handsome leaves, as yet undescribed, 

 in the upjier Eocene (Jackson formation) of 

 Texas; and a ver}- characteristic seed has 

 recently been described ' from the middle 

 Eocene (Claiborne group) of Mississippi as the 

 type of a new genus, Eoachras. 



A large number of fossil forms of Sapotaceae 

 have been referred to the form genus Sapota- 

 cites proposed by Ettingshausen (also Sapoto- 

 phyllum). At least 10 Upper Cretaceous forms 

 are widespread in North America and are rep- 

 resented in Europe in the Perucer beds of 

 Bohemia and the Credneria stage of southern 

 Saxony (Cenomanian). Three of these Upper 

 Ci'etaceous forms from the Tuscaloosa forma- 

 tion of Alabama undoubtedly represent the 

 ancestors of some of the Wdcox forms. There 

 are about 10 recorded species of Sapotacites in 

 the Eocene of France and southern England. 

 There are about a score of species in both the 

 Oligocene and Miocene, most of which are 

 European, though there is an undescribed spe- 

 cies in the Apalachicola group of western 

 Florida. In the Pliocene there are species in 

 southern Europe and on the island of Java. 



Notwithstanding the incompleteness of the 

 record, the family obviously became well dif- 

 ferentiated during the Upper Cretaceous, and 



1 Berry, E. W., Am. Jour. Sci., 4th ser., vol. 39, pp. 208-213, pi. 1, 1915. 



thougli it would not he safe to assign its ])lace 

 of origui to the American region, it is probable 

 that at least several of the genera, such as 

 Bumelia, originated in this region. 



The faniLIy Ebenacew includi^s about 8 

 genera and more than 300 existing shrul)s and 

 trees, of wliic-h over half are referred to the 

 genus Diosp>Tos Linne. Tlie family is mamly 

 tropical, as are most of the species of Diospy- 

 ros, though that genus is represented in the 

 North Temperate Zone in eastern North Anuu- 

 ica, eastern Asia, and the Mediterranean re- 

 gion. The 3 modern nionotyi)ic genera, Tetra- 

 clis, Brachynema, and Rhapidanthe, are con- 

 fuied, respectively, to Madagascar, Brazil, and 

 West Africa, and none have been found fossil. 

 The genus Royiuia is mostly South African; 

 Euclea is enth'ely confnied to Africa; Maba, a 

 large genus, ranges fi'oin Africa eastward to 

 Polynesia; and Macreightia is common to 

 tropical Africa and America. 



Dios]3;\Tos, which includes about ISO exist- 

 ing species, is cosmopolitan. Between 90 and 

 100 fossil forms have been described. In that 

 grand display of dicotyledonous genera which 

 during the middle-Cretaceous replaced the old 

 Mesozoic flora of ferns, cycads, and conifers, 

 and which appearctl with such apparent sud- 

 denness in many localities m the Northern 

 Hemisphere, we find unmistakable evidence of 

 the abundance and wide distribution of species 

 of Diospyros. No less than 17 different 

 forms have been described from the rocks of 

 this age, and the localities are scattered from 

 Australia to Bohemia, Greenland, and Vancou- 

 ver Island. Nearly aU these species are Ameri- 

 can, and they seem to have been especially at 

 home along the Cretaceous coast of the Atlan- 

 tic and along the border of the Mediterranean 

 Sea which extended northwestward from the 

 GuK of Mexico over much of our present Great 

 Plains area. One of these species, weU named 

 Diospyros primseva by Heer in 1866, is espe- 

 cially widespread and abundant. It occurs 

 not only in Iowa, Kansas, and Nebraska in the 

 West, but also from Texas eastward through 

 Alabama and northward in South Carolina, 

 North Carolina, Maryland, New Jersey, Long 

 Island, and Greenland, or from latitude 33° 

 to latitude 71° north. That these early per- 

 simmons were not VvU'y different from those of 

 to-day is shown by tlieir similar foli-age. This 

 resemblance is also tliowii by tin; fossilized 



