An uncommon tree of wet woodlands, riverbanks and heathlands, alder buckthorn displays pale green flowers in spring, and red berries that turn purple in autumn.

The alder fly is a blackish invertebrate, with delicately veined wings that it folds over its body like a tent. It can be found near ponds and slow-flowing rivers; the larvae living in the silt at…

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.

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.

Water-soldier grows submerged in ponds and open water, and pops up over summer, looking like the top of a pineapple! This rare plant displays white flowers and shelters many aquatic insects.

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.