As its name suggests, Himalayan balsam is from the Himalayas and was introduced here in 1839. It now an invasive weed of riverbanks and ditches, where it prevents native species from growing.

This bumpy shell lives up to its name and lives partly buried in the seabed along the west coast of Great Britain.

Cotoneaster was introduced to the UK in 1879 from Eastern Asia as an ornamental plant. It is now an invasive non-native species which is taking over valuable habitats including limestone…

Sea-buckthorn is a spiny, thicket-forming shrub of sand dunes. It's native to the east coast of England but considered an invasive species elsewhere. It is most obvious in autumn when it is…

A non-native species originating from Asia, the harlequin ladybird is prevalent in towns and gardens.

Yellow corydalis is a familiar 'weed' of gardens, walls and rocky places. It is a garden escapee in the UK, so is not a native plant. Try choosing natives for your garden to prevent…

The White-clawed crayfish is a freshwater, bronze-coloured crustacean with pale undersides to its claws - hence the name. It is under threat from an invasive and introduced species of crayfish.…