Often seen carpeting the floor of ancient woodlands, Dog's mercury can quickly colonise, its fresh green leaves shading out rarer plants. It is also very poisonous.

The gudgeon is a bottom-dwelling fish, similar to the stone loach, but with only two whisker-like barbels near its mouth. These sensory organs help it to find its prey in the sand and gravel of…

Look for the star-like, feathery, white flowers of Bogbean in ponds, fens, bogs and marshes. It is so-named because its leaves look like those of broad beans.

Despite its warts and ancient associations with witches, the common toad is a gardener's friend, sucking up slugs and snails. It is famous for migrating en masse to its breeding ponds.

The emperor dragonfly is an impressively large and colourful dragonfly of ponds, lakes, canals and flooded gravel pits. It flies between June and August and even eats its prey on the wing.

The Norway spruce was introduced into the UK from Scandinavia in the 16th century. It is familiar to us all as the 'original' Christmas tree and displays hanging, reddish-brown, oblong…

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.

A recent colonist to south east England, the metallic-green willow emerald damselfly spends much of its time in the willow and alder trees that overhang ponds, lakes and canals.

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.

In April and May, our ancient woodlands are awash with the much-loved, nodding heads of the bluebell. Millions of bulbs can exist in just one wood, giving rise to the 'blue carpets' that…

The stone loach is notoriously hard to spot - not only is it mostly nocturnal, it is also well camouflaged and can partially bury itself in the riverbed. It uses its whisker-like barbels to find…

The banded demoiselle can be seen flitting around slow-moving rivers, ponds and lakes. The males are metallic blue, with a distinctive dark band across their wings, and the females are a shiny…