ellipticaBryophyllum pinnatumCallisia fragransChromolaena
invasive species is a
naturalized species that causes or is likely to cause economic or
ecological/environmental harm or harm to human health. (Some indigenous
species also have the same effect in disturbed areas and under some
definitions are considered invasive as well).
Because it is impossible to determine
whether species arrived naturally or were introduced by Amerindians, I
define an introduced alien as any species which has arrived in Saint
Lucia from the colonial period onwards.
naturalized species is an introduced alien (non-native) species that
spreads into the wild and whose reproduction in the wild is sufficient
to maintain or increase its population.
of our naturalized species are
found in areas which have been altered by human activities such as
cultivation, animal husbandry, charcoaling, clearing for settlements
and modification of drainage pattern. The rain forest reserve and the
Pitons remain relatively free of naturalized species but the Pitons are
now under threat by the rapid spread of two Commelinaceae (Callisia fragrans and Tradesacant zebrina, both garden ornamentals).
list below is of species already invasive or could become so based on
what has happened elsewhere in the world. However other exotics present
in Saint Lucia could become invasive decades after becoming established.
(Many common grasses are also invasives but I have not listed them).
- native invasiveClidemia hirta
- native invasive
Coccinia grandisCordia obliquaCryptostegia
strigocamaraLeucaena leucocephalaMikania micrantha
- native invasiveMimosa pigraNephrolepis
browniiOeceoclades maculataPistia stratioidesRubus
rosifoliusScaevola taccada Spathodea
podophyllumTradescantia spathaceaTradescantia zebrinaTriphasia trifolia