Endemism means that a plant or animal is only found in one particular place. For example, many species of lemur are endemic to Madagascar.
Paleo-endemism and Neo-endemism are two sub-groups.
Paleo- means a species that had a large population but now has a small one.
Neo- means a new species, or one that has formed following hybridization. Neo-endemism is more common in plants.