Arrowhead is an aquatic plant of shallow water and slow-moving waterways. In bloom over summer, it displays small, white flowers, but it is the arrow-shaped leaves that are most distinctive.

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.

A low-growing plant of sand dunes, heaths and grassy places, Common centaury is in bloom over summer. Look for clusters of pretty, pink, five-petalled flowers.

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.

With club-shaped leaflets on its fronds, wall-rue is easy to spot as it grows out of crevices in walls. Plant it in your garden rockery to provide cover for insects.