Fen orchid  (Liparis loeselii)

Calcareous: containing free calcium carbonate, chalky.
Colonise: establish a colony (group of organisms living together).
Colony: a group of organisms living together, individuals in the group are not physiologically connected and may not be related, such as a colony of birds. Another meaning refers to organisms, such as bryozoans, which are composed of numerous genetically identical modules (also referred to as zooids or 'individuals'), which are produced by budding and remain physiologically connected.
Dune slack: depressions between sand dunes that are often wet during the winter.
Subspecies: a different race of a species, which is geographically separated from other populations of that species.