COMPOSITION OF TIIK FLORA. 



117 



Six well-marked types of Cliiuaiudinuin 

 leaves are descriltcd from the Wilcox i^roup, 

 some of tliem al)Uiidant and generally distriV)- 

 uted, and all hut two a|)|)('ar to l)e new to 

 science. In adtlitioii l)uds and llowers that 

 suggest this genus are descrihed luuler th(^ form 

 genus Lam'ophyUuin. 



There are 2 species of Persea in the Wilcox 

 flora. Besides the fossil forms referred to 

 Laurus in a comprehensive sense there are 

 about 50 known fossil species of Persea, which 

 is about the number of the existing species. 

 All si.x of the Upper Ci-etaceous forms are. 

 widely distributed in America. By Eocene 

 times they had reached Europe and South 

 America and tliey are cosmopolitan in the 

 Northern Hemisphere throughout the Tertiary, 

 being especially al)un(hint in the Pliocene of 

 the Mediterranean region. It would seem as if 

 their Cretaceous origin was occidental, that 

 they spread over the Northern Hemispliere 

 dm-ing the Tertiary and became restricted to 

 southeastern Asia, the ("anary Islands, and 

 America during the Pleistocene. 



The genus Ocotea Aublet, wliich includes 

 more than 200 existing species, is, it seems to 

 me, composite, and I regard the 3 genera 

 Mespilodaphne, Oroodaphne, and Strychno- 

 daphne of Nces as distinct. The modern species 

 of Mespilodaphne are confined to South Africa 

 and tropical .Vmerica. Tlie fossil record is 

 almost entirely merged in the forms referred to 

 Laurus. I have recognized 4 well-marked 

 species in the Wilcox flora, which are abundant 

 types. Some of them range from the base to 

 the top of the deposits and along the Wilcox 

 coast from Mississippi around the head of the 

 embayment and westward to Texas. 



The genus Oreodaphne has been recognized 

 in the Americain Upper Cretaceous and thi'ough- 

 out the European Tertiary. At present its 

 numerous species are confined to the American 

 Tropics. In the Wilcox it is represented by 7 

 weU-marked species, wliich are abundant indi- 

 viduaUy, some of which range from Mississippi 

 to Texas and from the base to the top of the 

 Wilcox. The genus is probably of American 

 origin and it has been a member of the flora 

 of the American Tropics from the Upper (^re- 

 taccous to the present. 



The geologic history of the genus Nectandra, 

 which includes 70 existing species that are 

 confined to tropical and subtropical America, 



is prol)ably entangletl witii I he fossil forms 

 referi-ed to Laurus. It occurs in the American 

 Upper Cretaceous and the Eiu'opean and Soutli 

 American Tertiary. There are a) least .5 char- 

 acteristic Wilcox species, some of which were 

 abundant along the Wilcox coasts, and some 

 I'ange from the base to the top of the de- 

 l)()sits. Like Oi'eodaplnie, tiiis genus apjjcars 

 to liave been of American origin, becoming cos- 

 mopolitan in the Tertiary and restricted to its 

 original liome during tlie i'leistocene, wher(> it 

 is still a vigorous and much differentiated type. 



T]i(> triltes Eusidci-oxyknr, Litseea?, Apol- 

 l(uhea\ Acrodic'lidiea', Laurea:', and Cassythea^ 

 do not appear to be represented in tlm Wilcox 

 flora, altiiough the Litseea- ar(> re|)resented in 

 the I'pper Cretaceous of the Mississippi em- 

 l)ayment ai-ea and the Laurea> are common in 

 the American Upper Cretaceous. The tribe 

 Cryptocaryese, now largely American, is repre- 

 sented in the Wilcox by a single weU-marked 

 species of Cryptocarya. The existing species 

 of (^ryptocarya number about 40, one-fourth 

 of which are South American and the rest 

 Oriental. Only 2 or 3 fossil species are known. 

 They com(> from the Tertiary of jVustralia and 

 Soutli jWeriea and the Pleistocene of Java. 



The form genus Laurus, which serves to 

 render insecure the discussion of the geologic 

 history of the preceding genera, includes a very 

 large number of fossil fonns, of which no less 

 than 25 are Cretaceous, the oldest of which 

 come from the Albian of France and Portugal. 

 Species of Laurus are abundant throughout 

 North America in the Cenoinanian, ranging 

 northward to Greenland, and they also occur 

 in Europe and Australia. There are more than 

 a score of species in the Eocene and these have 

 a smiilar wide range. The 30 or more Oligo- 

 cene species are confined to Europe. More than 

 30 Miocene species are confined to Europe and 

 America, and the score of Pliocene species are 

 Mediterranean and largely ItaUaii. 



1 will mention only one other genus, since it 

 definitely shows a past history that is probably 

 typical of a large number of genera of Lauracea-. 

 The genus Sassafras,' which is monotypic and 

 confined to Noi'th America in the existing flora, ^ 

 belongs to a large tribe — the Litseeae, which 

 to-day is chiefly oriental, ranging from Asia 



' Berry, E. W., Bot. Gazette, vol. 34, pp. 426-4.W, ng.<!. 1-4. pi. IS, 1902. 

 - A second existing species has recently been discovered in .south- 

 western China. 



