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 distinctive spiky, or 'bearded', green flower heads of wall barley appear from June to July and are easy to spot in an urban environment as they push their way up through pavements…

A common thistle of roadside verges, rough grassland and waste ground, the Musk thistle has large, purple, nodding flower heads that appear in summer. It is attractive to a wide range of insects…

As its name suggests, pendulous sedge has drooping form with long, nodding flower spikes that give it an attractive and soft look. It can be found in wet woodlands and along riversides.

As its name suggests, Himalayan balsam is from the Himalayas and was introduced here in 1839. It now an invasive weed of riverbanks and ditches, where it prevents native species from growing.

Looking like a short dandelion, but with a much rounder middle, colt's-foot is a 'weed' of waste ground and field edges that brightens up early spring with its sunshine-yellow…

A clever mimic, the wasp beetle is black-and-yellow and moves in a jerky, flight-like fashion - fooling predators into thinking it is actually a more harmful common wasp. Look for it in hedgerows…