Invasive plants in Scotland (United Kingdom)
An audit made by Scottish Natural Heritage in 2001 identified 988 non-native species occurring in Scotland, UK. The following plants are currently causing problems in Scotland:
Aquatic plants: Elodea canadensis (Hydrocharitaceae), Elodea nutallii (Hydrocharitaceae, EPPO List of invasive alien plants), Crassula helmsii (Crassulaceae, EPPO Alert list).
Terrestrial plants: Rhododendron ponticum (Ericaceae, EPPO List of invasive alien plants), Reynoutria japonica (Polygonaceae, EPPO List of invasive alien plants), Impatiens glandulifera (Balsaminaceae, EPPO List of invasive alien plants), Heracleum mantegazzianum (Apiaceae, EPPO List of invasive alien plants), Hyacinthoides hispanica (Asparagaceae).
The native Hyacinthoides non-scripta is threatened by competition from and hybridization with Hyacinthoides hispanica. Hybridization produces a fertile hybrid which may then pollinate further wild populations and dilute the native species still further.
Sources
Scottish Executive website