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…

Bell heather is our most familiar heather. In summer, it carpets our heaths, woods and coasts with purple-pink flowers that attract all kinds of nectar-loving insects.

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.

The pretty-in-purple Pasqueflower is now a rare plant in the UK, restricted to just a few chalk and limestone grasslands. Steeped in legend, it flowers at Easter, so is known as the 'anemone…

With a silvery body, and purple, pink and bluish streaks down its flanks, the rainbow trout lives up to its name. Popular with anglers, it is actually an introduced species in the UK.

The pretty-in-purple amethyst deceiver can be seen growing in the leaf litter of our woodlands during late summer and autumn. Although edible, it looks similar to the poisonous Lilac fibrecap.

Bittersweet is a nightshade, so is toxic; its bright red berries may be tempting, but can cause serious illness. Found in hedgerows and gardens, it has purple flowers with yellow stamens.

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 Coppery click beetle is a large, coppery-purple beetle with straw-brown wing cases. It can be found on grassland and farmland, and its larvae are known to feed on roots and damage crops.

Eyebright has small, white flowers with purple veins and yellow centres. It likes short grasslands, from clifftops to heaths, and is one of a number of species and hybrids that are hard to tell…