320 



LOWER EOCENE FLOliAS OF SOUTUEASTKKN XOKTU AMERICA. 



Family COMBKETACEffi. 

 Genus LAGUNCULARIA Gartner. 

 Lagunculaeia preracemosa Berry, n. sp. 

 Plate XCV, figures 4-8. 



Description. — Leaves somewhat variable in 

 size and outline, elliptical or olilong-elliptical. 

 Length 4 to 6 centimeters, averaging about .5 

 centimeters. Maximum width, midway b(>- 

 tween the apex and tlic base, 2 to 2.5 centime- 

 ters. Apex more or less broadly roundetl in 

 specimens slightly emarginate. Base a coun- 

 terpart of the apex in outline. The lateral 

 margins may be approximately parallel witli 

 the broacUy rounded apex and base or they may 

 be gently and ecjuaUy curved in both directions 

 from the region of maximum width, and in 

 these specimens the apex and base are more 

 narrowly rounded. Petiole short, stout, and 

 curved, about 4 mdlimeters in length. Midrib 

 stout and straiglit. Secondaries thin, numer- 

 ous, and camptodrome, diverging from tlie mid- 

 rib at -nade angles and immersed in the leaf sub- 

 stance. Margins entu-e. Texture coriaceous, 

 slight^ rugose. Fruit turbinate, several 

 ribbed, ligneous, the corona composed of sev- 

 eral rather long, somewhat recurved coriaceous 

 acute teeth, presumably a one-seeded coriace- 

 ous drupe as in the modern species. 



This species is one of those rare fossil forms 

 represented by both foliage and fruit, for 

 though the leaves and fruit were not found in 

 organic union they are associated in the same 

 deposits, and I have no doubt were borne 

 by the same tree, since both are character- 

 istic. 



Both tlie leaves and fruit ai'e so mucli like 

 those of the existing Laguncularia i-acemosa 

 Gartner that it seems reasonably certain that 

 tliey represent its Eocene progenitor. Tlie 

 leaves are almost identical with the existing 

 species in outline and venation and have the 

 same thick rugose textm'c, the oidy difference 

 being in the somewhat shorter petioles of the 

 fossils and their lack of tuberculafiou on the 

 surface in the margiiuil region. The fruits are 

 also nearly identical with those of the existing 

 species. They are shorter and relatively 

 Ijroader and the coronal teeth, are longer and 

 fewer in number, thus resembling more nearly 

 tlie uiirij)e fruits of the existing species. The 

 number of ribs is probably the same as in the 



existing form, l)iit this feature can not 1)e made 

 out positively. 



The genus Laguncularia is moiiotypic in the 

 existing flora, and its single species, Laguncu- 

 laria raccinosa Gartner, the buttonwood or 

 white mangrove, inhabits muddy tidal shores 

 of estuaries and lagoons. It is common m 

 southern Florida southward from Cape Cana- 

 veral and Cedar Keys, in Bermuda, and through- 

 out tropical America — the Bahamas, Antilles, 

 Mexico, Central America, and northern South 

 ^Vmerica. It is also found along the west coast 

 of Africa in the equatorial belt. Although I 

 know of no experimental evidence, this distri- 

 Inition woidd indicate that the small ligneous 

 fruits withstand submergence for long periods 

 and that the species is distributed by ocean 

 currents. 



Laguncularia preracemosa is one of those for- 

 tunate finds which enable the student to piece 

 together the scraps of evidence and to build up 

 a reasonable picture of the ])hysiography, cli- 

 mate, and ecologic grouping of the Wilcox flora. 

 This is, so far as I know, the first recorded 

 occuiTi-nce of a fossil species of Laguncidaria, 

 and though Tertiary species with leaves of simi- 

 lar outline have been described, for example, 

 MininsiUs adenarttliei'a Unger ' from Radolx)] in 

 Cj'oatia, there is little difficultj' in distinguish- 

 ing them. 



There are also similar leaves of unrelated 

 species in the AVilcox flora that might in the ab- 

 sence of the rare fruits be confused with the 

 present species. These are the following forms : 

 Mimusops sieberifolia Berry, which is found in 

 the same deposits as Laguncularia preracemosa 

 but is distinguishable by its more elongate form, 

 slightly revoliite margin, and much more promi- 

 nent and different venation; Sophoraunlcoxiaria 

 Berry, also found at Puryear, Tenn., whose leaf- 

 lets are thiiuier and slightly inequUateral, and 

 have a different venation and an almost obsolete 

 pctiolule; Cassia tvilcoxiuri a Berry, in which the 

 outline of the leaves is much like the most taper- 

 ing forms of Laguncularia, but the venation is 

 somewhat different and the leaflets are sessile. 



Occurrence. — IloUy Springs sand, Holly 

 Springs, Marshall County, Miss, (collected by 

 E. W. Berry). Lagrange formation (in beds of 

 Wilcox age), Puryear, Ilemy County, Tenn. 

 (collected by E. W. Berry). 



Collections. — U. S. Natioiud Museum. 



1 Unger, Franz, Dio fossile Flora von Itadoboj, i>. 153, pi. 3. flg. 2, 1809. 



