Bahaman Region: Insular Area. 695 
High Thicket Formation. In this type of thicket in New Providence, there is 
very little undergrowth on the densely shaded ground. The largest tree of this coppice which 
covers the southern slope of the Blue Hills on the Bahama black loam soils is Lysiloma latisi- 
liqua, the wild tamarind. Swietenia mahagoni, Simaruba glauca and Pera bumeliaefolia are also 
large trees. 
The high-coppice formation on Watlings Island consists of large trees. Here are found 
in association Gymnanthes lucida, Guaiacum sanctum, Bourreria havanensis, Ichthyomethia pisei- 
pula, Bursera simaruba, Acacia choriophylla, Tecoma bahamensis, Thouinia discolor, Chiococca 
parvifolia, Humelia microphylla, Cajanus cajan, Citharexylum quadrangulare, and such vines as 
milax Beyrichii and Serjania subdentata, together with Thrinax bahamensis. 
On Long Island the most abundant constituents of this formation are Lysiloma bahamensis, 
Rapania guyanensis, Guaiacum sanctum, Erythroxylon brevipes, Tetrazygia bicolor, Krugiodendron 
ferreum, Tecoma bahamensis, Caesalpinia vesicaria, Zanthoxylum caribaeum, Reynosia septentrio- 
nalis, Amyris elemifera, Maytenus buxifolia, Gymnanthes lucida, Exostemma caribaeum, Hypelate 
trifoliata, Torrubia longifolia and Bursera simaruba, which reach a common height of 15 to 20 feet. 
Tropic Forest Formation. On Mangrove Cay, Andros, the botanist en- 
counters, according to COKER, a true forest where are found Zysiloma pauci- 
folia, L. latisiligua, Zanthoxylum coriaceum, Hypelate trifoliata, which reach a 
height of 40 to 50 feet, while as secondary species 30 to 40 feet tall may be 
mentioned Coccoloba laurifolia, Rhus Metopium, Ichthyomethia piscipula and 
Stwietenia mahagoni, all contributing to a thick growth and dense shade. 
b) Floridan Area. 
Phytogeographically this area comprises the southern extremity of peninsular 
Florida and the keys (cays) which lie off its coast. The geology of southern 
Florida is similar to that of the Bahama islands and the botanist would natu- 
rally exspect to find, that controlled by the edaphic conditions, there would 
be many species of plants in common. A statistic enumeration shows this to 
be the case. The honey-combed limestone rock supports a luxuriant vege- 
tation and a reference to a former page (229—232) will present the main 
facts concerning the principles underlying the distribution of Floridan plants. 
The following are the principal plant formations of this area: 
Mangrove Formation. The mangrove formation represents an important 
element in the flora of southern Florida. The mangrove swamps are parti- 
cularly abundant along salt or brackish shores and along the sea islands, the 
so-called Florida Keys‘). Their vegetation is confined almost exclusively to 
the mangroves (Rhizophora mangle) and such few Tillandsias and orchids as 
grow upon their branches. Frequently on the borders of these swamps occur 
a large, showy fern Acrostichum aureum. Many of the keys are surrounded 
by a girdle of mangrove trees. 
In detail, according to the botanic exploration of the sand keys west of Key West by LAnsınG?) 
the mangrove formation is distributed, as follows: Key C. consists almost entirely of a colony of 
ı) PHirLips, O. P.: How the Mangrove Trees add new Land to Florida. Journal of Geography 
II: 1—14; Smarz, J. K.: Report on Exploration in tropical Florida. Journal New York Botanical 
Garden V: 49 March 1904; VaucHan, T. WAyLanD: “The geologic Work of the Mangroves in 
southern Florida. Smithsonian Miscellaneous Collections LII: 461—464 with 6 plates. 
2) MitzspaucH, C. F.: Sand keys of Florida (1907): see Bibliogr. p. 90. 
