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.

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…

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…