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.

As its name suggests, giant hogweed it a large umbellifer with distinctively ridged, hollow stems. An introduced species, it is an invasive weed of riverbanks, where it prevents native species…

Horseradish is used as a well-loved condiment. This member of the cabbage family is actually an introduced species in the UK, but causes no harm in the wild.

The turnstone can be spotted fluttering around large stones on rocky and gravelly shores, flipping them over to look for prey. It can even lift rocks as big as its own body! Although a migrant to…

This well-camouflaged woodpecker used to be a common breeding bird in Britain, but is now only likely to be seen passing through on migration.

This sponge is found on rocky shores around the UK and looks like a thick bready crust (if you use your imagination a bit!).

Introduced from Japan in the 19th century, Japanese knotweed is now an invasive non-native plant of many riverbanks, waste grounds and roadside verges, where it prevents native species from…

Perennial rye-grass is a tufted, vigorous grass of roadside verges, rough pastures and waste ground. It is commonly used in agriculture and for reseeding grasslands.