The tightly packed, thistle-like purple flower heads of common knapweed bloom on all kinds of grasslands. Also regularly called black knapweed, this plant attracts clouds of butterflies.

The ragged-edged, purple flower heads of Greater knapweed bloom on sunny chalk grasslands and clifftops, and along woodland rides. They attract clouds of butterflies.

Broom is a large shrub of heaths, open woodlands and coastal habitats. Like gorse, it has bright yellow flowers, but it doesn't have any spines and smells of vanilla.

Common couch is a tall, tuft-forming grass of roadside verges, waste ground and arable land. It is very tough and can shade out more delicate plants. Look for flat, blade-like leaves and thin…

Introduced from Japan in the 19th century, Japanese knotweed is now an invasive non-native plant of many riverbanks, waste grounds and roadside verges, where it prevents native species from…

On first glance, the meadow thistle looks a bit like a knapweed - it's not as prickly as other thistles and only carries one pinky-purple flower head. It can be found in damp meadows and…

The six-spot burnet moth is a day-flying moth that flies with a slow, fluttering pattern. Look for it alighting on knapweeds and thistles in grassy places. It is glossy black, with six red spots…