A notoriously poisonous plant, hemlock produces umbrella-like clusters of white flowers in summer. It can be found in damp places, such as ditches, riverbanks and waste ground.

A beautifully scented plant, the arching stems and bell-shaped flowers of Lily-of-the-valley can be seen in many woodlands. Despite its delicate appearance, this plant is highly toxic.

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.