As its name suggests, Himalayan balsam is from the Himalayas and was introduced here in 1839. It now an invasive weed of riverbanks and ditches, where it prevents native species from growing.

Cotoneaster was introduced to the UK in 1879 from Eastern Asia as an ornamental plant. It is now an invasive non-native species which is taking over valuable habitats including limestone…

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…

An attractive, olive-green bird, the greenfinch regularly visits birdtables and feeders in gardens. Look for a bright flash of yellow on its wings as it flies.

The blue-tailed damselfly does, indeed, have a blue tail. It is one of our most common species and frequents gardens - try digging a wildlife pond to attract dragonflies and damselflies.

The smaller of our two UK seal species, common seals are also known as harbour seals. Despite being called "Common", they are actually less common than grey seals!

As the name suggests, the common medium stonefly is found in gravelly upland rivers and streams, often on bankside stones and plants. There are 34 species of stonefly in the UK, which are hard to…

Common mouse-ear is a persistent 'weed' of fields and gardens, verges and hedgerows - all kinds of habitats. But, like many of our weed species, it is still a good food source for…

The London plane tree is, as its name suggests, a familiar sight along the roadsides and in the parks of London. An introduced and widely planted species, it is tough enough to put up with city…

Like many of our farmland birds, the yellowhammer has declined in number in recent years. Spot this bright yellow bird singing from the top of a bush or fence, or in a mixed-species flock in…

The sweet chestnut is famous for its shiny brown fruits, or 'chestnuts', that are wrapped in a spiky, green casing and make a tasty winter treat. Look for this tree in woodlands in south…