Don't know where this is supposed to go (which forum category) as Rhipsalis has such a wide and unique distribution.
it is common knowledge among cactophiles that cacti occur only in the New World. however there is an exception to this which is the epiphytic genus Rhipsalis which as well as being present in the rain forests of much of South and Central America, occurs throughout a large part of central Africa, Madagascar, the Comores, Seychelles, Mascarenes and even Sri Lanka. In fact, unique members of the genus not found in South America exist outside the New World.
a good site about Rhipsalis:
'The Rhipsalis Riddle - or the day the cacti came down from the trees', by Phil Maxwell
(long but very interesting read):
There are many theories regarding why Rhipsalis are found outside the range of the rest of the Cactacae family, but Maxwell will explain these and the beliefs behind them, and provide a personal opinion.