Bermuda is a small island chain in the eastern Atlantic, located at 32° 18' N Lat. (same as Jackson MS or Savannah GA) and 64° 46' W Lon. (similar to and about halfway between Halifax, Nova Scotia and San Juan, Puerto Rico). Cape Hatteras is the closest mainland point, and New York City is the nearest major port.
It is bathed in the Gulf Stream, and winter temperatures seldom dip below 50° F (monthly averages are 19-30° C). Humidity tends to be high (77%), and rainfall averages 56 inches or 146 cm. per year.
Bermuda is a 50 km.2 island chain 30 km. long and at most 3km. wide, with elevations up to 80m. It was formed volcanically, but those formations is now almost entirely below sea level. The current land consists of fossilized sand dunes formed from wind-blown bits of ground coral. There is also some reddish soil, deposited dust blown in from the Sahara Desert in Africa. Some has been transformed to organic matter by plants and animals.
The porous limestone does not accommodate standing fresh water, so ponds are low-lying and brackish. Drinking water must be obtained by roof collection and cistern storage, or by desalinization.
Bermuda has cyclically drowned and reemerged as ice ages have alternated with warmer times. As a result, Bermuda's oldest life forms are relatively recent. The most recent cold period was 20,000 years ago; the most recent hot period was 100,000 years earlier. Before human exploration in 1500's and colonization in 1609, there were no mammals nor amphibians, and only one reptile, an endemic skink.
More than half of the current flora and fauna have been introduced.
Bermuda currently has 19 ferns and Psilotum, a sort of club-moss. Five of these are introduced species. Of the 14 native ferns, 2 are endemic or nearly so.
Another endemic and three native species have been reported, but are not currently extant.
The historic endemic, Diplazium laffanianum, has been preserved in captivity; there are five (-2 +?) plants remaining. Efforts at propagation are underway.
This website has photographs of every extant Bermuda pteridophyte and two of the four historic species (though five of the pictures were taken on the U. S. mainland.)
*Some of this information is copied from an online article by Wolfgang Sterrer: HOW MANY SPECIES ARE THERE IN BERMUDA?