The brown hairstreak is an elusive butterfly that spends much of its time in the treetops feeding on aphid honeydew.

This well-camouflaged wader is a winter visitor to the UK, where it can be seen feeding on wetlands with a distinctive bobbing motion.

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…