Our only venomous snake, the shy adder can be spotted basking in the sunshine in woodland glades and on heathlands.

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.

Bladder campion is so-called for the bladder-like bulge that sites just behind the five-petalled flower - this is actually the fused sepals. Look for it on grasslands, farmland and along hedgerows…

The adder's-tongue fern is so-named because the tall stalk that bears its spores is thought to resemble a snake's tongue. An indicator of ancient meadows, it can be found mainly in…

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.

This brown seaweed lives in the mid shore and looks a bit like bubble wrap with the distinctive air bladders that give it its name.

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…