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.

A tall plant, purple-loosestrife can form dense stands of bright purple flower spikes in wet habitats like reedbeds, fens and marshes.

Pineappleweed is an introduced species that has become a widespread 'weed' of disturbed ground, such as pavements and roadsides and gardens. It has feathery leaves and yellow flower…

As its name suggests, Water dock likes damp places, such as the egdes of canals, ponds and rivers. It is a tall plant with large, greenish flower spikes.

Often found carpeting damp grassland and woodland clearings, the blue flower spikes of bugle are very recognisable. A short, creeping plant, it spreads using runners.

A familiar 'weed' of gardens, roadsides, meadows and parks, red clover has trefoil leaves and red, rounded flower heads. It is often used as fodder for livestock.

Bladder campion is so-called for the bladder-like bulge that sites just behind the five-petalled flower - this is actually the fused sepals. Look for it on grasslands, farmland and along hedgerows…

The pincushion-like, lilac-blue flower heads of Devil's-bit scabious attract a wide variety of butterflies and bees. Look for this pretty plant in damp meadows and marshes, and on riverbanks…

As its name suggests, the Dwarf thistle is a low-growing plant that is almost stemless - its purple, thistle-like flower heads growing out of a rosette of spiny leaves.

A prickly, tall plant, the Small teasel is closely related to the Common teasel, but has much smaller, more rounded flower heads. It prefers damp, open woodlands.