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.

The candlesnuff fungus is very common. It has an erect, stick-like or forked fruiting body with a black base and white, powdery tip. It grows on dead and rotting wood.

Famed for its tapping in the middle of the night, supposedly heralding tragedy, the Deathwatch beetle is a serious wood-boring pest. In houses, their tunnelling can cause major damage.

Bell heather is our most familiar heather. In summer, it carpets our heaths, woods and coasts with purple-pink flowers that attract all kinds of nectar-loving insects.

Cross-leaved heath is a type of heather that likes bogs, heathland and moorland. It has distinctive pink, bell-shaped flowers that attract all kinds of nectar-loving insects.

The chocolate-brown, plump dipper can often be seen bobbing up and down on a stone in a fast-flowing river. It feeds on underwater insects by walking straight into, and under, the water.

Piddocks are a boring bivalve. No, we don't mean dull... we mean that it bores into soft rock, creating a burrow. In fact, they're the opposite of dull - they glow in the dark!

A handsome fish, the tench has olive-green flanks, powerful fins and distinctive red eyes. It can be found in lowland lakes and slow-flowing rivers around the UK.

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.

Look for the White water-lily in still and slow-moving water, such as ponds, ditches, lakes and canals. Its lily pads and massive, white flowers float at the water's surface.

Look for the Yellow water-lily in still and slow-moving water, such as ponds, ditches, lakes and canals. Its lily pads and cupped, yellow flowers float at the water's surface.