Considered Britain's most threatened butterfly, the high brown fritillary can be only be found in a few areas of England and Wales.

Look for the round, cottony, purple flower heads of the Woolly thistle on chalk and limestone grasslands in summer. It is mainly found in Southern England.

A breeding bird of fast-flowing, upland rivers, the grey wagtail can also be seen in lowland areas, farmyards and even towns in winter.

This elegant tern is named for the rosy flush to its summer plumage. With just one regular nesting colony, it is the rarest breeding seabird in the UK.

Sand eels are a hugely important part of our marine ecosystem. In fact, the fledgling success of our breeding seabirds entirely depends on them.

The angel's wings fungus grows in overlapping clusters in the coniferous woods of Scotland and north England. Its funnel-like, white caps have no stems.

A scarce but distinctive brown seaweed with curved, funnel-shaped fronds. It is a warmer water species at the northern edge of its range on the south coast of England.

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 dazzling silver-studded blue is a rare butterfly of heathland habitats, mainly in southern England. It has undergone severe population declines in recent years.

Once widespread, this attractive plant has declined as a result of modern agricultural practices and is now only found in four sites in South East England.