An uncommon hedgerow and woodland tree of central and eastern England, Purging buckthorn displays yellow-green flowers in spring, and poisonous, black berries in autumn.

The Land caddis is the only caddisfly in the UK to spend its entire time on land, with no stage in water. Look in oak leaf litter over winter to see the grainy cases of the larvae, in which they…

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.

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.

These colourful little fish are a delight for snorkellers or shallow water divers to photograph, rarely being scared off by their presence!

The wayfaring-tree is a small tree of hedgerows, woods, scrub and downland. It displays creamy-white flowers in spring and red berries in autumn, which ripen to black and are very poisonous.

The lesser spotted woodpecker is the smallest of the UK's woodpeckers. Listen out for its drumming, which is quieter than that of the great spotted woodpecker, in woodland, parks , orchards…

Small-spotted catsharks used to be called lesser-spotted dogfish - which might be what you know them best as. It's the same shark, just a different name!

Bittersweet is a nightshade, so is toxic; its bright red berries may be tempting, but can cause serious illness. Found in hedgerows and gardens, it has purple flowers with yellow stamens.