Arrowhead is an aquatic plant of shallow water and slow-moving waterways. In bloom over summer, it displays small, white flowers, but it is the arrow-shaped leaves that are most distinctive.

An uncommon hedgerow and woodland tree of central and eastern England, purging buckthorn displays yellow-green flowers in spring, and poisonous, black berries in autumn.

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.

This sponge is found on rocky shores around the UK and looks like a thick bready crust (if you use your imagination a bit!).

The wigeon is a colourful duck that can often be spotted wheeling round our winter skies in large flocks. A dabbling duck, it surface-feeds on plants and seeds in shallow waters.

Flowering rush is a pretty rush-like plant of shallow wetland habitats, such as ponds, canals and ditches. Its cup-shaped, pink flowers appear in summer, brightening up the water's edge.