Freshwater pearl mussels spend their adult lives anchored to the river bed, filtering water through their gills and improving the quality of the water for other species.

Pineappleweed is an introduced species that has become a widespread 'weed' of disturbed ground, such as pavements and roadsides and gardens. It has feathery leaves and yellow flower…

Water-cress has become so popular as a salad addition that it is now cultivated on a wide scale. In the wild, it grows in shallow, fast-flowing streams and is an indicator of clean water.

One of the most eye-catching sights on the rocky shore, this mind-boggling species resembling a collection of beautiful pressed flowers is actually a colony of individual animals!

The turtle dove is the UK's fastest declining bird species and is on the brink of extinction. A small and pretty pigeon, it breeds in lowland England and winters in Sub-Saharan Africa.

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.

A classic fern of woodlands across the UK, the male-fern is also a great addition to any garden. It grows impressive stands from underground rhizomes, dying back in autumn.

One of the most colourful fish in UK seas, the cuckoo wrasse looks like it belongs in the tropics. Don't be fooled though, it's very much a native species.

The White-clawed crayfish is a freshwater, bronze-coloured crustacean with pale undersides to its claws - hence the name. It is under threat from an invasive and introduced species of crayfish.…