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.

Despite its name, Ground-ivy is actually a member of the dead-nettle family. It is a clump-forming, aromatic plant that likes woodlands, hedgerows and damp places.

Native oysters are a staple of our seas and our plates - but our love of their taste has lead to a sharp decline all around the UK.

Red squirrels are native to the UK but are a lot rarer than their grey cousins. They live in a few special places across the UK thanks to reintroduction projects.

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.

A tall and hairy plant, Great willowherb displays pretty pink-and-cream flowers. It can be found in damp places, such as wet grasslands, ditches and riversides.

The Marsh helleborine is a beautiful orchid of fens, wet grassland and dune slacks. Growing in profusion in places, look for reddish stems and white-and-pink flowers.

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.

A low-growing plant of sand dunes, heaths and grassy places, Common centaury is in bloom over summer. Look for clusters of pretty, pink, five-petalled flowers.