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 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.

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.

Sometimes called 'Marsh samphire', wild common glasswort is often gathered and eaten. It grows on saltmarshes and beaches, sometimes forming big, green, fleshy carpets.

The raven is famous for being the imposing, all-black bird that guards the Tower of London. Wild birds live in forests, and upland and coastal areas in the north and west of the UK.

A scarce tree of England and Wales, the Large-leaved lime is the rarest of our native limes. It is tall and broad, and can be found in forests and parks, where it is frequently planted.

Water-cress has become so popular as a salad addition that it is now cultivated on a wide scale. In the wild, it grows in shallow, fast-flowing streams and is an indicator of clean water.