1. Flora

The flora corresponds to the diversity of plant species in a specific area. The flora of Cocos Island is related to that of the continent, particularly with that of Central America and northern part of South America, and was dispersed by migrant birds, winds, ocean currents and floating materials.

The highest percentage of species of vegetation on the island is similar to the flora of the biogeographic area of the Guyanese-Amazonian provinces of the Neotropical region. This explains how reproductive and vegetative materials arrived from the continent to the island, which occurred at some time during the Pliocene-Pleistocene period. This occurred before the Central American isthmus was closed in the area of Panama and when the outflow from he rivers, including the Magdalena and Orinoco Rivers, emptied into a common sea where there was a westerly circulation of currents that transported botanical material to Cocos Island.

Although there is a dense and exuberante vegetation on the island, there is not a great diversity of species. About 135 species of phanerogams (plants with flowers and seeds) have been identified, of which two-thirds correspond to dicotyledons and one-third to moncotyledons, both containing 7.4% of endemic species. Seventy-four species of ferns and similar plants have been reported, with a 6.6% rate of endemism. The mushroom flora is abundant considering the small land area of the island; 85 species have already been identified, although it is estimated that this represents only half of the existing species. To date, the bryophytic flora includes 162 species, of which 56 are mosses and 106 are liverworts. These species are similar to those of the Neotropic (54%), Caribbean (9.7%) and Pantropic (10.4%), with an endemism of 3.2%. Also identified on the island are 99 species of foliicolous lichens, which are related to Pantropical (61%), Neotropical/African (14%), Neotropical/Australasian (4%), Neotropical (16%), Australasian (1%), with an endemism of 3%.

Therefore, from a botanical point of view, Cocos Island can be considered a separate biogeographic unit in the eastern tropical Pacific Ocean. It constitutes a genuine botanical garden of tropical plants that include elements of several biogeographical regions. An analysis of the current knowledge about the diversity of the flora, of its biogeographical relationships and of its endemism, demonsrate its exceptional nature and its high scientific interest.