Traditionally a coastal species, Lesser sea-spurrey has spread inland, taking advantage of the winter-salting of our roads. Its pink-and-white flowers bloom in summer.

One of the most colourful fish in UK seas, the cuckoo wrasse looks like it belongs in the tropics. Don't be fooled though, it's very much a native species.

The stinging nettle is a familiar and common plant, often firmly rooted in our memories after our first, hands-on experience - a prickling irritation that's not forgotten easily!

When spotting the pintail in winter, look out for the fabulous, long tail feathers that characterise it. This dabbling duck feeds at the water's surface, rather than diving for food.

Lilac is an introduced species in the UK that can sometimes be found in hedgerows and along woodland edges. Flower spikes appear in spring, beautifully scented and packed with small, lilac-pink…

The nodding, pink-and-purple-chequered flowers of the snake's-head fritillary are said to resemble a snake, hence the name. Declining with the loss of our meadows, this delicate plant can be…

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.