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.

Curled dock is often considered a 'weed'. It can be found near water or on disturbed ground almost anywhere. It is similar to Broad-leaved dock, with which it can hybridise.

A familiar garden bird, the blue tit can be seen around bird tables and feeders, as well as in woodlands and parks. Listen out for its trilling, 'tsee-tsee-tsee' song. It is smaller than…

A low-growing plant of sand dunes, heaths and grassy places, Common centaury is in bloom over summer. Look for clusters of pretty, pink, five-petalled flowers.

A notoriously poisonous plant, hemlock produces umbrella-like clusters of white flowers in summer. It can be found in damp places, such as ditches, riverbanks and waste ground.

Pepper saxifrage is a classic plant of unimproved hay meadows and roadside verges. It's upright, branching stems carry umbrella-like clusters of creamy-yellow, flowers in summer.

Selfheal is a low-growing, creeping plant that likes the short turf of grasslands, roadside verges or even lawns. Its clusters of violet flowers appear in summer.

Water-plantain is an aquatic plant of shallow water and muddy banks. In bloom over summer, it displays tall branches of loosely clustered, pale lilac flowers.

The delightful fragrance of wild thyme can punctuate a summer walk over a chalk grassland. It forms low-growing mats with dense clusters of purple-pink flowers.

Common alder can be found along riversides, and in fens and wet woodlands. Its exposed roots provide shelter for fish, and its rounded leaves are food for aquatic insects.

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.

Caddisflies are a large order of insects that can be found in all kinds of wetlands. The larvae are known for making cases to pupate in, gathering stones, sand and leaves, and wrapping them with…