The river lamprey is a primitive, jawless fish, with a round, sucker-mouth which it uses to attach to other fish to feed from them. Adults live in the sea and return to freshwater to spawn.

Considered to be one of the prettiest gentians, the Chiltern gentian is a rare plant in the UK. It likes chalk grasslands, its purple, trumpet-shaped flowers blooming from August.

Creeping jenny is a low-growing plant of wet grasslands, riverbanks, ponds and wet woods. It has cup-like, yellow flowers and is a popular choice for garden ponds.

The early gentian is a rare plant that is only found in the UK. It likes sunny, lowland chalk grasslands, its purple, trumpet-shaped flowers blooming in May and June.

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…

A small and delicate plant of chalk grasslands, Fairy flax can be seen in bloom from May to September - look out for its nodding, white flowers.

Greater celandine is a very common plant that spreads easily in the garden, on waste ground and in hedgerows. It is considered a weed, but the small, yellow flowers provide nectar for insects.

Hedge mustard is a tall plant with small, yellow flowers atop tough stems. It likes disturbed ground and grows in hedgerows and roadside verges, and on waste ground.

The pungent, rotten smell of Black Horehound makes this medium-sized plant of waste ground and roadside verges stand out from the crowd.

The unpleasant, astringent smell of Hedge woundwort makes this medium-sized plant of woodlands, hedgerows and roadside verges stand out from the crowd.