With a silvery body, and purple, pink and bluish streaks down its flanks, the rainbow trout lives up to its name. Popular with anglers, it is actually an introduced species in the UK.

Look for the pretty, azure-blue flowers of Wood forget-me-not along woodland rides and hedgerows, and in ancient and wet woodlands. Varieties of this flower for the garden are very popular.

A tall and robust species of sedge, the Great fen-sedge has long leaves with sawtooth edges. It forms dense stands in lowland fens and around lakes.

The grey squirrel was introduced into the UK in the 1800s. It provides an easy encounter with wildlife for many people, but can be damaging to woodlands and has contributed to the decline of the…

Look for Water avens in damp habitats, such as riversides, wet woodlands and wet meadows. It has nodding, purple-and-orange flowers that hang on delicate, purple stems.

Look for the wood warbler singing from the canopy of oak woodlands in the north and west of the UK. Green above, it has a distinctive, bright yellow throat and eyestripe.

Living up to its name, the hairy violet is covered in fine hairs. Look for its delicate, violet flowers blooming from March to June on chalk grasslands, in particular.

As its name suggests, the ruby elfcup is a bright red, cup-shaped fungus. It is widespread, but scarce, and can be found on fallen twigs and branches, particularly in areas with higher rainfall.…

Wavy hair-grass lives up to its name: its fine, hair-like leaves and delicate flower heads can be seen shaking in the breeze of a windswept moorland or heathland.

A familiar 'weed' of gardens, roadsides, meadows and parks, red clover has trefoil leaves and red, rounded flower heads. It is often used as fodder for livestock.

Common laburnum is an introduced species, planted in parks and gardens. It is most recognisable in flower - its hanging bunches of yellow blooms giving it the name 'Golden rain'. It is…

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.