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.

Selfheal is a low-growing, creeping plant that likes the short turf of grasslands, roadside verges or even lawns. Its clusters of violet flowers appear in summer.

Water-plantain is an aquatic plant of shallow water and muddy banks. In bloom over summer, it displays tall branches of loosely clustered, pale lilac flowers.

Pushing its way up through the cracks in pavements, the straw-coloured flower spikes of greater plantain or 'broadleaf plantain' are a familiar sight. This 'weed' also pops up…

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.

The yellow, star-like flowers of bog asphodel brighten up our peat bogs, damp heaths and moors in early summer, attracting a range of pollinating insects.

The delightful fragrance of wild thyme can punctuate a summer walk over a chalk grassland. It forms low-growing mats with dense clusters of purple-pink flowers.

Common mallow is a handsome 'weed' of waste ground, roadside verges and gardens. Its deep pink, stripey flowers provide nectar for insects throughout the summer.

A late-flowering plant, Autumn gentian displays pretty, mauve, tube-like flowers atop its reddish stems. It favours dry, chalk grassland and sand dune habitats.