Elements of probably neotropie origin. 
_ Clitoria mariana L. 
"Crotonopsis linearis Michx. 
Ascyrum stans Michx. 
Hypericum densiflorum Pursh. 
(Sarothra) Drummondii 
rev. ook. 
virgatum Lam. 
 Rhexia mariana L. 
" Jussiaea decurrens Walt. 
Gelsemium sempervirens Ait. 
Cynoctonum mitreola L. (= Mitreola 
petiolata G.) 
Spigelia marylandica L. 
N Callicarpa americana L. 
Gratiola sphaerocarpa EIl. 
zn. >» 
| 
N 
N 
227 
Yeatesia laete-virens Buckl.(—=Y. viridi- 
ora Nees.). 
Diodia virginiana L. 
Melothria pendula L. 
Eupatorium aromaticum L. 
Chrysopsis graminifolia Michx. 
Silphium asteriscus L. 
Tetragonotheca helianthoides L. 
Coreopsis major Walt. (= C. seni- 
folia Michx.). 
Coreopsis auriculata L. 
Marshallia lanceolata Pursh var. pla- 
typhylla Curtis. 
Liatris (Lacinaria) graminifolia Walt. 
Pluchea petiolata Cass.. 
» viscosa Schwein. Silphium compositum Michx. 
Bignonia crucigera L. (= B. capreo- | Helianthus angustifolius L. 
ata L.) Helenium nudiflorum Nutt. 
.j* 
By far the greater number of these neotropic species in the above list be- 
long to groups, whether genera, tribes, or families, which are chiefly tropic 
in their distribution. Thus of the three most largely represented families, the 
Gramineae, the species belong chiefly to the tribes Andropogoneae and Pani- 
ceae; and the Compositae to Eupatorieae and Helianthoideae. This category 
is remarkable in consisting almost entirely of herbaceous species. Most of 
them are of distinctly xerophytic structure, loving a dry sandy soil and much 
light and heat. 
The extremity of peninsular Florida is remarkable from a floristic stand- 
point in the presence of so many tropic species many of which have been 
received through the Bahama islands and perhaps some of them directly from 
the Greater Antilles. In all probability part of this migration occurred during 
the Eocene period for during the Eocene elevation there was probably a land- 
way from Cuba across the Bahama banks to Florida, as evidenced by geology 
and by the fact that certain groups of Antillean land mollusks according to 
ORTMANN’) crossed that bridge. Perhaps this land connection continued until 
Miocene times, or at any rate peninsular Florida was then identified with the 
Bahama islands for geologists have proved that during this time the Gulf 
Stream did not form any barrier to plant distribution northward because it 
flowed out of the American Mediterranean, as now, but through a passage 
across the northern half of Florida. 
Subsequent to the Miocene, the Bahama islands were again submerged for 
1) ORTMANN, A. E.: The geographical Distribution of freshwater Decapods and its Bearing 
upon ancient Geography. American Philosophical Society XLI: 267—400. 1902. 
16” 
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