The Land caddis is the only caddisfly in the UK to spend its entire time on land, with no stage in water. Look in oak leaf litter over winter to see the grainy cases of the larvae, in which they…

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…

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…

As its name suggests, the Dwarf thistle is a low-growing plant that is almost stemless - its purple, thistle-like flower heads growing out of a rosette of spiny leaves.