coMi'osrnox OF the flora. 



115 



at least. rciVi-al>l(' to tliis family, so tliat ciioui^h 

 is kllo^v^l of the geologic history of the group to 

 confirm at least the statement previously made 

 that it must have had a long and complex history. 



The family Lauracea\ which includes al)out 

 1,000 existing species distributed among 40 to 

 50 genera, is often placed next to the family 

 ^Vnonacete among the Ranales.' It may be 

 noted, however, that the spiral arrang(>ment 

 of floral organs characteristic of the order 

 Ranales is replaced by a cyclic' arrangement, 

 and liypogyny is also replaced by epigyny, so 

 that I follow various students in referring 

 the Lauracca? to the order Thymeleales, the 

 other large family of wliich, the Th_ymela>aceffi 

 (not known in Wilcox flora), contains about 

 400 exist mg species, chiefly of temperate 

 Australia and the Cape region of Africa. 



The geographic distribution of tlie Lanracete 

 can not be set forth as briefly as the classifica- 

 tit)n, since there are not only many anomalies 

 in the distribution of the existing species, but 

 so much of the geologic historj- is kno\\'n that 

 the difficulties seem increased therel)y rather 

 than diminished. Thus the existing species of 

 the family arp divided into 8 tribes, no one of 

 which, except the monotypic Eusidoroxylese 

 of Borneo, is restricted to a smgle continental 

 region. 



The largest of these tribes, the Cinnamomeie, 

 includes more than 500 species endemic on all 

 the continents but Europe, though cliiefly 

 Asiatic and America)!. The 4 genera Persea, 

 Phoebe, Notaphocbe, and Mespilodaplme are 

 found in both hemispheres: Cinnamomum and 

 Machilus are oriental; and Oreodaphne, Strych- 

 nodapline, Nectandra, Pleurotliyrium, Um- 

 bellularia, Dicypellium, and Synandrodaplme 

 are occidental. The first tlu'ee of these genera 

 are large, and the last four are monotypic. 



The tribe Litseese, which includes 6 genera 

 and about 200 species, is represented on all the 

 continents except Europe and Africa. Only 

 9 of these 200 species are found in the Oc(;iden.t, 

 yet among these is the monotypic North 

 American genus Sassafras, and the genus 

 Sassafridium which is confined to the American 

 Tropics. All the other genera are found on 

 more than one continent. 



The tribes Apolloniese, Cryptocaryeie, and 

 Cassythese are found on all the contments but 



'Engler, A., and Prantl, K., Die natilrlichen Pflanzenfamilien, 

 1SS7-1901. 



Europe. Tlie i.aure* are Eurasiatic and the 

 Acrodicli(Uea>, are confined to Cc^ntrul and Soutli 

 America, except the genus Endiandra,, whicli 

 comprises 16 species in the East Indies and 

 Australia. 



The problem of correctly identifying leaves 

 of the genera of this family is beset with almost 

 insurmountable difficulties, not tho least of 

 which are tlie wide differences in usage among 

 students of tho recent forms, whore the whole 

 jilant is available for study. Long-continued 

 paleobotanic practice has Ixhmi to refer most 

 fossil loaves that lackiHl the morc^ apparent 

 characters of Cimiamomum oi' Sassafras, Persea 

 or Malapcemia, and the like, to the compre- 

 hensive genus Laurus, a practice adopted at a 

 time when Laurus was used in a comprehensive 

 sense. Some paleobotainsts generalized still 

 further, as by usmg Laurophyllum for laura- 

 ceous leaves of uncertain generic affinity and 

 not necessarily close to the_ existing species of 

 Laurus. In fact the species of LaurophyUum 

 are in general not true species of Laurus. I 

 have departed from this practice of describing 

 new species of Laurus for many reasons, fore- 

 most among which is the very great affinity 

 between the Wilcox flora and the existing flora 

 of the American Tropics, so that the evidence 

 from the foliage of a large number of genera is 

 corroborated by fruits or seeds or wood anat- 

 omy. I have used tliis similarity with a great 

 deal of confidence, perhaps with too much, and 

 the result has been that the following stand out 

 as the more important lauraceous types in the 

 Wflcox flora. Nearly all these forms are seem- 

 ingly members of the subfamily Persoidese of 

 the tribe Cinnamomese, as segregated in Engler 

 and Prantl's "Natiirlichen Pflanzenfamilien." 



First, the genus Cuuiamomum, usuaUy 

 readily recognized and certainly represented in 

 our Eocene floras. 



Second, the genus Persea, represented by the 

 larger and wider forms with the typical vena- 

 tion of this genus. 



Third, tho genus Nectandra, so abundant and 

 characteristic of the existing flora of tropical 

 and subtropical America, representcMl by sev- 

 eral species very close to motlern forms. 



I have f aUed to f oflow the latest usage, which 

 recognizes the genus Ocotea as sucli, since for 

 obvious reasons it seems wise to recognize the 

 genera Mespilodapluie and Oreodaphne of Nees 

 rather than to regard them as subgenera of 



