West Indian Section, Antillean Region. 673 
their flora is of different origin and much younger in point of time than that 
of the Greater Antillean chain. For convenience, and because the division is 
a natural one, the flora of the Antillean Region has been divided into four 
districts, as follows: Cuban, Jamaican, Santo Domingan and Puerto Rican dis- 
tricts. Each of these will be considered separately, although they possess many 
phytogeographic features in common, as for example, a similar strand and 
mangrove vegetation. 
A. Cuban District. 
This phytogeographic district comprises the Island of Cuba, the Isle of 
Pines and outlying islands and keys. It is difficult in the absence of exact 
data to give an account of the plant formations of this district; but a general 
sketch, which will give the salient features of its flora, is of importance. 
The flora of Cuba is noted for a large number of endemic types and 
also for the striking character of those types, their occurrence and their 
distribution. A comparison with the flora of Florida shows a great difference, 
while a comparison with Central and South America shows it to be almost 
identic with them in general character; and this is probably due to two 
facts: (1) Cuba and the other Greater Antilles were at one time connected 
intimately with Central and South America '), and their floras practically identic 
(see map ante p. 172); (2) The Gulf Stream washing the shores of northern 
South America is deflected from the coast of Central America into the Cari- 
bean Sea, carrying all tropic seeds over into the West Indies. Cuba’s great 
coast line and its proximity to the stream, a part of which flows along the 
south coast and a part making a circuit of the Gulf of Mexico, striking the 
north coast of Cuba, would greatiy favor the reception of such seeds. — T e 
distribution of the flora over the Island is very interesting. The gro diffe- 
rent kinds of soil, the altitude, the proximity to the sea, all combine to make 
a diversified flora., & 
Presumably the Mangrove Formation in Cuba is similar to those swamps 
that occur in the other West India Islands where Ahzzophora mangle, A 
cennia nitida, Conocarpus erectus and Laguncularia racemosa Are prominent. 
The Isle of Pines is completely surrounded by mangrove vegetation. = The 
Dune Formation includes the sandy beaches and sand dunes found in many 
parts of the island. 
In general, the flora of such sandy places has much in common wich similar a in 
other parts of the Antillean archipelago. The plants of the sand dunes ın Cuba E_ ur 
maritima, Sesuvium portulacastrum, Borrichia arborescens, Ipomoea pes-caprae, Euphor 1a Mar 
Ximenia americana, Maytenus buxifolia, Tephrosia cinerea, Verbesina encelioides, Jusieh (A ap 
origanoides, etc. e sandy soil or sandy flats are marked by the presence of u Be 3 
Corchorus hirsutus, Malpighia coceigera, Myginda rhacoma, M. ilicifolia and Pisonia discolor. 
—_ 
1) Guppv, R. J. Lechmere: The geological Connexion of the Caribean Regions. Trans. 
Canadian Institute VII: 373—391. 1908—1909. 5 
Harshb erger, Survey N,.-America, 43 
