A tall plant, purple-loosestrife can form dense stands of bright purple flower spikes in wet habitats like reedbeds, fens and marshes.

The delicate, tube-like, violet-blue flowers of Skullcap bloom from June to September in damp places, such as marshes, fens, riverbanks and pond margins.

The Welsh poppy is a plant of damp and shady places, roadsides and hillsides. It is also a garden escapee. It flowers over summer, attracting nectar-loving insects.

Often found carpeting damp grassland and woodland clearings, the blue flower spikes of bugle are very recognisable. A short, creeping plant, it spreads using runners.

The Common walnut tree produces a large, brown nut that is familiar to so many of us. It is an introduced species in the UK, and can be seen in towns, gardens and parks.

A tall and robust species of sedge, the Great fen-sedge has long leaves with sawtooth edges. It forms dense stands in lowland fens and around lakes.

Ground-elder was likely introduced into the UK by the Romans and has since become naturalised. A medium-sized umbellifer, it is an invasive weed of shady places, gardens and roadsides.

A notoriously poisonous plant, hemlock produces umbrella-like clusters of white flowers in summer. It can be found in damp places, such as ditches, riverbanks and waste ground.