Information authenticated by Tim Rich of the National Museums and Galleries of Wales.
Annual: lives or grows for just one year.
Biennial: A plant that lives for two years and typically flowers only in the second year.
Calcareous: containing free calcium carbonate, chalky.
Colonise: establish a colony (group of organisms living together).
Perennial: plants that live for at least three seasons; after an initial period they produce flowers once a year.