Introduced from Japan in the 19th century, Japanese knotweed is now an invasive non-native plant of many riverbanks, waste grounds and roadside verges, where it prevents native species from…

Look out for the small, yellow flowers of Celery-leaved buttercup in wet meadows and at the edges of ponds and ditches. It flowers from May to September.

Frogbit looks like a mini water-lily as it floats on the surface of ponds, lakes and still waterways. It offers shelter to tadpoles, fish and dragonfly larve.

As its name suggests, Water dock likes damp places, such as the egdes of canals, ponds and rivers. It is a tall plant with large, greenish flower spikes.

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.

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.

The bronze-coloured bream can be seen gathering in large shoals in lowland ponds, lakes and slow-flowing rivers. It is a member of the carp family and looks similar to the dace, chub and rudd.

A member of the buttercup family, Common water-crowfoot displays white, buttercup-like flowers with yellow centres. It can form mats in ponds, ditches and streams during spring and summer.

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.